This may be my personal opinion but I don't think any links you posted are examples of a composer failing to remake his own music, so ???
Squeenix + Uematsu have proved more than competent in arranging FF music (FF7 in particular) with their constant efforts in the FF piano collections, the Black Mages, Earthbound Papas, and the Distant Worlds concerts.
It would be a breeze for them to redo the FF7 music, especially with live instruments given their experience and resources. Rarely on OCR do you see someone who just records a full orchestra for their stuff with ease.
There's good intentions behind sourcing it to the fans, but I don't think there's anyone better suited to it than professionals. We *do* have many professionals here, so yes, it's possible that OCR could pull it off with really tight quality control, but why do you think Squeenix would bother when they have their proven talent with decades of experience and better resources?
That being said, writing for the FF7 remake would be a dream come true for everyone, so dreaming is okay. ;P
There's also the issue of implementation. Video game composing isn't just about writing tracks and sending them to the game developers, so I'm sure the devs would appreciate having a music team to communicate with instead of an internet forum community.