For everyone: the FB user confirmed me that the mention of the pre-order DLC coming in April was relatively to the swimsuits. Nothing about the Premier sexy, Showstoppers Encore or NINJA 2015, it's very likely that all these pack will come deffered in the time. Imo it's not a cade that in April, May and June we will get only a new DLC set, maybe because the other 2 weeks will be used for releasing each time a part of the preorders packs.
@Argentus I can confirm that Mila can toggle off her mask with the shinobi outfit, just as expected. By the way this is the only customization possible, you don't have the possibility to apply the band aid. Finally, being an exclusive of the current gen, I don' have way to test if the alternative hairstyle of Mila is selectable with the mask on/off, but I suppose that the answer is yes having seen other characters do it (as Tina).