I think we can assume that Sephiroth killed them in his merry jaunt through the Shinra HQ.
Noctis, your idea of the Turks' role in *superior imaginary AC* is quite nice. That's the thing about the Compilation. It's given such a rich, vibrant world to work with (we spent 80 hours there) and if a post-game world is what they're going with, there are all sorts of things to do with who is still alive. Reno's lovely last words in the OG "If we both survive... if we can save our lives..." is filled with double meanings. If it wasn't for the original AC footage treating Reno and Rude like Laurel and Hardy, their scenes in ACC would be really impactful, and the best part of the Compilation.
Instead, we get fanservice. And yeah, I know it's nothing to be shocked at. It would be 'foolishly optimistic' of me to assume that an organization would be more involved in creating art than revenue. As an artist myself, though, I can't help but hoping.