"Luna having a style of affluent people" means very little. The privilege of wealth is that she can dress in a vast swath of fashions available; contemporary fashion is broad from culture, history, and the enhancements of the technologies available today to make different fabrics and clothing. Yet her design was made with simple white dress, blonde hair, blue eyes, soft demeanor. It's evident even from visual design that Luna is supposed to be a 'pure beautiful nice princess', the equivalent of being a trophy. It's not a strong fashion sense; it's just a dull dress intended to reflect a boring character.There's so much to cover in this and your previous post.
Luna being an upper classman dresses in a way that fits portraying someone with grace and strong fashion sense for simple aesthetics. Her style is not out of the norm for affluent people. I do agree that the trailer so far gives hints of her being that strong supportive character and while that it is generally problematic trope I take into context the team that is working it while you prefer to ignore the team in favor of the wider development culture.
When games like Elder Scrolls and Kings Quest clearly had leading women in less than desirable depictions Final Fantasy was always the forefront in pushing less of an emphasis on showing skin for modesty or flamboyance, having female characters with parts far better than their contemporaries of their time period to having gameplay roles with stats that wasn't a joke or only supportive.
You're positioning your argument as if SquareEnix has a systemic problem when at a fundamental level they've gone against the grain and made some of the best representations of women in gaming throughout history.
It's fine to say what's shown so far is regressive for Square but I don't think Square should avoid doing it all. People have strengths and weaknesses in different ways and I don't see anything wrong with Square experimenting with something that's not normal for them. Personally I hope in the game they actually put a spin on this but even if they don't I doubt this means they are heading towards a totally new direction in character depiction that leans heavily on decades old stereotypes they've pushed against before.
Going back to your point about Cid and how they pretty much make a requisite sexy character that is only about showing off their body. It's true that they have at least one dressed like that but up until now they also had interesting backstories or powerful roles (playable or not).
So Cid is atypical be being totally eye candy especially since her father makes her redundant.
The inclusion of Cid as a short cut to adding a female element you lust for is a missed opportunity by Square to build up on past games where characters form short as well as long term relationships. A big part about being in a group of guys is learning together how to interact with women so this was another way in game bonding that could've been developed if they took more time than just making someone everyone lusted after whenever she came around to fix their car.
A character who would walk in wearing this is infinitely more interesting, stylish, and likely present more of a personality than what Luna's visual design conveys. It is the developer's choice to make Luna look the way she does, so there aren't excuses, it's just natural that she would look like that because they aim for a specific type of boring supportive girl character.
Games of the west have been working to modify their products according to feedback. Even Call of Duty is exhibiting initiative in having a diverse cast and better characterization of these characters. The linking of old marketing material in this thread and the insistence of FF's merits in the past do not reflect the current state of FF or the evolution of the industry and the environment post-GamerGate. Has the industry not changed since 2006, where these 12 trailers and these AC trailers are being linked as if they were proof of anything? Even back then FF was not at the forefront of pushing less emphasis on fanservice elements on female characters: Tifa, the tight suit of Garnet emphasizing her ass, Lulu bending over to jiggle her boobs as a victory pose, the fanservice costumes of 10-2, the designs of Ashe and Fran in 12, Vanille having a plot mark on her butt, the reduction of Lightning to a dress up doll over the 13 trilogy. Pre-7 they could get away with sketchy designs because of sprites.
By now, with Luna and Cidney, it is evident that FF is backsliding. Part of this is not the fault of Square; after all, they cannot control the cultural proclivities of Japan. But unlike Tales, or Star Ocean, or even Persona, which rides the line between niche and something more successful than niche, FF has the advantage of global success and mainstream access. Yet the developers felt the urge to put in garbage like Cidney, when they don't need to pander to that market to sell more. For Dragon Quest, SE does not need that sort of material for mainstream success, yet you find your puff-puffs and your va va vooms and your bikini clad female characters in there too. For Mobius, SE responded to complaints about the male character design, but complaints about female character design in 15 fell to deaf ears. Is there not something inherently wrong there?
Making "some of the best representations of women in gaming throughout history" is not a high bar when the portrayal of women in gaming is rubbish to begin with. SE has not been a leader in game design, story, character, tech, anything for 10 years; for FF15, we have stooped to asking them to meet the new, 2016 baseline for female characters. Rather than standing apart from the crowd of otaku-oriented female designs, SE has stuck their feet in the pool, and ignored feedback that suggested they should get out before they get deeper.
If tech is what hobbled Japan in the PS360 gen, what will hobble them in HD games from here on out is something substantially more difficult: a divergence in the culture and tastes of the western market from the culture and tastes of the domestic Japan market. The mainstream of Japan has moved to mobile; to sell console games they have to pander to otaku. But that market is nowhere near big enough to repay the cost of developing a big budget JRPG like a mainline FF. To tackle that, yes, Square has to avoid doing Cidney-like pandering. They have to write female characters that appeal to more than domestic Japanese men. They have to get to growing their audience, not shrinking it. Cidney-types, Luna-types, those are not the way to go.