This is why I said "in YoshiP we trust". Right now I'm giving them the benefit of the doubt, but I'm not about to ignore red flags either. The truth is we don't know how this game is going to go with regard to its female characters, so we shouldn't be getting down on people for feeling some kind of way about potential issues when the last mainline entry did set a poor precedent.
In fairness to XV -- and owing largely to the decision to present its narrative in a fragmented form -- basically anyone who wasn't Noctis was lucky to get a thoroughly explored present and backstory. And for that matter, going off the base game itself at launch, even he didn't get that.
If we go with all of the media available at launch (the game, the movie, the OVA, and the little audio drama) ... I guess Prompto does alright in that regard? But not even that much better than Lunafreya or Ravus?
If we look at the final state of the game plus all DLC and other media, Gladio still doesn't come out all that great. Prompto and Ignis
do come out great, as do Lunafreya and Aranea. Iris and Cidney do slightly less well than Gladio. Ravus and Cor arguably do better than Gladio.
Really, there's so many ways to approach analyzing XV on this -- but given that there's not a whole lot of character
development for anyone who isn't Noctis (just character exploration), most of the cast comes out about the same relative to one another. We get to know who they are in the present and a general sense of what makes them who they are. Even Cidney had this in the base game.
Now, inarguably we spend less time with any female characters than we do the Chocobros, but that's a whole separate topic from how they're handled when they are around -- and also a mostly unavoidable result given the deliberate (one-off) design structure of the story as a roadtrip between bros. If looking at this metric, we end up with some wildly different results again depending on the point in ongoing support for the title we look at and what media we're including.
Going off just the base game at launch, of the female cast, Iris and Aranea do best in this regard by far, and comparable to one another. Incorporating all media at the launch of the game, Lunafreya probably comes out a little better than they do. Taking stock of the final state of the game plus all DLC and media, Lunafreya comes out better (in exploration, development, time spent with her, etc.) than
most FF female characters. Aranea comes close to this. Iris and Cidney are now far behind -- but probably still not too far behind Gladio.
tl;dr: There's nothing to be worried over.