Final Fantasy 7 was such a successful game that it went ahead and spawned a mini franchise all of its own, with multiple cross media projects dedicated to showcasing more of its world. These included spin off games that existed to flesh out the universe further- Crisis Core: Final Fantasy 7 for the PSP (and actually directed by Hajime Tabata, who would later on go to work on Final Fantasy 15); Dirge of Cerberus for the PS2; and Before Crisis: Final Fantasy 7, originally released for mobiles.
With Final Fantasy 7 getting remade, there may be fans who would like an HD compilation of all of these games too, so that they would have a consolidated collection to go to for the entire expanded Final Fantasy 7 universe. However, in an interview with Finaland (via Siliconera), Tetsuya Nomura, the director for the upcoming remake, said that this may be difficult to accomplish.
“Concerning Final Fantasy VII Remake, which is a title loaded with a lot of mystery for now, it will be different from the original Final Fantasy 7,” he said. “If we make a compilation, these games will hardly have an overall coherence. It will be difficult because there is no more continuity between the Compilation and the Remake for the moment.”
Which, I assume, is his way of saying that given how vastly different each of the spin offs were, the chances of something like this actually coming to pass are low. Final Fantasy 7 Remake is set to launch on the PS4 first… some time in the future. We don’t actually know when.