I guess....it just comes off as lazy and too transparently cynical of a cash grab to me. GT in terms of storyline was atleast preferable for being consistent with previous mechanics and lore as well as having a decent new super saiyan design.
GT had the characters knowing the ki of #19 and #17, even though androids couldn't be sensed in Z. It had Goku randomly using a technique from Movie 13. It had a Goku who ordered people to give energy to him rather than attempting to fight uselessly (Something I could never forgive it for. If you're going to give so much focus to Goku, don't miss his personality that badly).
It couldn't even remember how strong some of its characters were supposed to be (like how Uub somehow goes from above SSJ3 Goku level in the Baby Saga to barely above Goten/Trunks level when facing Super 17, and then is stated to be weaker than them in the final arc). Super sometimes has some pretty weak excuses for power ups, like Tagoma's and Freeza's training, but at least they realize that they're changing established power levels.
This new arc of bringing trunks back seemed like it could have atleast been interesting, but right off the bat it makes no sense to me...hopefully there are atleast some explanations somewhere
The arc hasn't even started yet though, obviously there wouldn't be explanation about the new plot elements at this point.
Also, as far as Trunks' hair go, it's also an inconsistency created by the original anime. Toriyama had both Bulma and Trunks with purple hair during most of the original run of the manga, while the anime gave blue hair to Bulma. In his modern work though, which was made with the anime in mind, he changed Trunks' hair to blue to match Bulma's - although, before this new arc, they always kept it purple in the actual animation. It shows that from Toriyama's point of view, what's important here is that both Bulma and Trunks should have the same hair color, so that's the consistency he's attempting to keep. Now, I don't know why the anime staff finally decided to make Trunks' hair blue too, but it's not a random inconsistency.
I'm not pretending it doesn't make sense, it literally doesn't. Just because its Dragonball and is going to rake in the cash doesn't mean it can't atleast try to stay consistent with previous established things, like everyone in Trunks time being dead, no Mai or anybody else to be seen, and Trunks hair being a specific color.
There were still surviving humans in Trunks' future. You're talking like any survivors popping up would be a plothole, which is just silly. As long as they aren't stated to be dead, I don't see why existing characters appearing is a plothole. IIRC, the anime version of the Trunks special shows that Roshi and Oolong survived too.