Yes, but that outfit is not appropriate to wear in battle.
Lightning
is sexy. But she doesn't need to get her tits out to do so. This is not fanart, this is an honest to god part of the game that Square Enix have included. You argue that it's an easter egg, but it's even easier to obtain - there is no Justin Bailey code to input, you're likely able to buy this at a store. Which implies that Lightning has either no reservations or actively enjoys wearing something like that, which has - in my opinion - been demonstrated as false throughout the previous two games.
Even her "goddess battle armour" was not overly sexualised. If you click
here, you can see there's a bit of thigh showing, but it is for all intents and purposes still battle-worthy armour, and covers her goddamn breasts up.
Lighting was supposed to stand on the
other side of
this trope but including her in revealing and out of character costumes as part of the game is undermining that.