Probably not. Going that old and you really start loosing connection with your demographic. I think that late 20s is the best we are ever going to do.

Personally for me, and creating a good level of immersion, you can't go too old or too young. If they are too young then having them be such a badass doesn't make sense. At the same time if they are too old then what have they been doing their whole life to all of a sudden turn the corner and just decide they are going to be awesome? That role usually is filled better by an older more experienced fighter who joins mid game and is already considered quite strong.

What I would like to see is a larger timeline progression on stories. FFT, as I imagine it, probably took place over a few years. Time for Ramza to build up his skills from well trained but typical squire to one of the best fighters in Ivalice. Having everyone go from village kids killing rats at the starting town to world savers in a few weeks really makes it hard to suspend my disbelief. So we get our older protagonists, but we grow with them to get to that point.