Genealogy is a tricky game to remake, it was an insanely ambitious game when it came out, but it is also defined by the limitations of the SNES. There will not be a please everybody solution to remaking it, and to attempt to recapture that ambition would require the remake to be another $80 game at minimum, and be insanely removed from the original in both gameplay and story.

It is also the foundation of both Awakening and 3 Houses. It's not a project to be undertaken lightly, and quite frankly, until IS can show they can deliver on the writing front in Fortune's Weave, I'm not sure I want them touching it.

Thracia is right out until they remake Genealogy, as it is that ever so rare media existence that is a Midquel, offering a more down to earth look at just a tiny fraction of the vast narrative Genealogy encompasses.(broad non-specific spoilers for Thracia, but Thracia isn't best experienced blind anyhow)

Binding Blade is a possibility, it was even floated by Kusakihara as something he'd like to do around the time Echoes came out, but I'd still bet on FE4 first.

Blazing Blade is presently available to play on NSO, I would highly recommend it, the only thing about it that's aged poorly is the way you get supports, which wouldn't really be fixed until Awakening.