Aeris was able to tell her Elmyra that her husband had died, but she wasn't able to tell that Zack had died. This was probably a mistake but I think it could be developed.

I don't think Aeris should be brought back from the dead because that woud just be changing the already perfect (for me) plot of ff7. You just have to accept that Aeris died for a reason, and that it was her destiny. Her death was one of the best FMVs in the game: Clouds touchiong speech, the sadness and mysteriuosness of it, the drama of it. If Aeris was brought back to life, that FMV would just be meaningless. Anyway, not everyone even likes Aeris.

It also keeps the game open. I shall be looking forward to a remake of ff7.