Although it does follow the pattern, I'm not convinced they're gonna do VII, because if they put in Sephiroth he'd overshadow Omega for many folks.

The only way I could actually see them doing a convincing Seph fight would be to have him actually be the last guy over Omega, which story wise doesn't work unless Seph gonna Seph and you find out he ganks Omega during the testing because he doesn't want to be his tool or something crazy (that SE would totally do because it's Sephiroth, lol).

Another way they could do VII though is sticking only to the Weapons. Have Diamond, Emerald, Ruby then Omega as the last.