I long ago stopped getting into these kinds of discussions when I realised that, at one time or another, every single aspect of characters like this is going to be criticised or picked apart one way or the other, regardless of whatever counterpoint we're going to have to say on the matter. And WW's costume will be no exception to the rule.
This character's appearance is going to be ridiculed by someone whichever direction they go, so they might as well just pick a direction and stick with it, knwoing that it'll be no more or less disliked than the other direction.
As for the film itself, I can't really say that I'm too excited about it. While the idea of seeing all of DC's big names on the big screen has it's appeal, I long ago resigned myself to the idea that (in Bob's own words) Warner Bros is just bad at making superhero movies that aren't entirely about Batman.
As such, I'm not expecting this version of WW to be that interesting, regardless of her costume choice, especially since my personal definitive version of her character was already done over a decade ago by Bruce Timm and his team.