We already know this year's six characters (The three remaining are Balrog, Juri & Urien and will probably release in that order), so we already have Sakura de-confirmed. She's likely to show up eventually though, and is probably a very strong candidate for 'Season 2' next year.
Also keep in mind: most of the characters who have been changed ship with some sort of 'classic costume' for story mode, which can be unlocked. Ken has his long Alpha hair and red gi, Guile gets his tank top back and loses the sunglasses, etc. It's highly likely that Ibuki (and Juri, since we know her costume is changing significantly) will have their 'classic' styles represented in the free-to-unlock story costumes, so eh. The default costume is meant to represent where that character is at in this point in the SF timeline, so it is what it is.
Equally because of this when Sakura shows up if Capcom stick to the sensibilities about costumes they kept talking about running up to pre-release she shouldn't be a schoolgirl any more. A slightly 'grown up' Sakura will be fun to see, so hopefully that's the route they go with her.
