What I find funny and is almost never addressed, is that the cataclysm 2000 years ago with Jenova speading her HIV around has been low key unleashed again and no one seems to notice or care. This bitch wiped out the ancients, and her body is taken out of stasis and her cells injected into dozens of men.

The jenova fought right at the end appears to be a new body or the original body from the Shinra HQ since it looks totally different.

Advent Children kind of tied this up with Geostigma. Though it seems to create an infinite sequel possibility in that Seph-Jenova can't be absorbed by the life stream and thus will be a cancer in the planet forever.