I suppose that's true, but it's not like all songs fall in that category right? Like the aforementioned Zero from Bump of Chicken. Anyway's I did some digging and it doesn't seem like Gackt had any musical involvement with Crisis Core, it was only his likeness that was used for Genesis.Eyes on Me is a song written and composed by then Square Enix composer Uematsu. While Faye Wong singing the song could be an issue, it's not really when Squeenix owns the song outright I believe. Unlike say Gackt doing music for CC or any licensed music from any Jpop act or Leona Lewis.
Fuck you, I want to have Angeal's babies!
I can see them leaving out Angeal and Genesis in the remake but Zack is popular enough to make it over just fine.
Zack is in FF7, of course he will be in the remake and it has nothing to do with popularity, he's like the big plot reveal.
Fwiw, this is what Nomura said last year:It's strange how the game never got released digitally. With 7R coming it'd be a great time to release so people can play as Zack again.
Tetsuya Nomura Hints at FF7 Remake Spinoffs, Including Revisiting Compilation of Final Fantasy VII
"I'm thinking about ideas regarding the remake's release – I even spoke to producer Kitase about it today. All of us old-timers are considering various developments in regards to what accompanies the remake. Like if we can manage to do something about the [Compilation of Final Fantasy VII] titles too. But for the time being, please wait for VII's turn to come."
Source.
100%I feel like they will incorporate things from Crisis Core into the remake.