Exaggerations aside, there's more to the Viera gear seeming inappropriate than how much skin it covers. For me at least, it's more about the style and the materials - if this secluded jungle tribe were wearing the same amount of clothing in sturdy cloth and leather, that would make perfect sense. But elaborate black metal and sheer fabrics look incredibly out-of-place, if that's what they're supposed to be wearing "at home" and doing whatever it is they normally do.
The high heels definitely don't help the impression, and is entirely about looks over function - if they are naturally digitigrade they firstly shouldn't need the heeled shoe to support it, and secondly should be in a more crouched stance so they can balance properly, not tiptoeing about while standing as tall as possible. It makes sense for a fashion model, but not for a jungle tribe.
(Of course, it's possible once we get to the Viera settlement, they'll be wearing outfits as far from their starter gear as the Xaela nomad robes are to Auri "traditional" starter gear.)
I also dislike the specific choice of using Fran's costume when Fran herself is already in the game - I don't think they've thought through the fact that now and forevermore, from the perspective of a new player not familiar with other FF games, the Viera character in the Lv70 raid doesn't get a unique costume but is wearing the exact same gear that all Viera have been wearing since level 1.
