I mean, typically they've only done one set of remakes per generation of hardware, haven't they?
GBA - Fire Red/Leaf Green, Gen 1 remake DS - Heart Gold/Soul Silver, Gen 2 remake 3DS - Omega Ruby/Alpha Sapphire, Gen 3 remake Switch - Brilliant Diamond/Shining Pearl, Gen 4 remake (I am not counting Let's Go since that isn't really a traditional Pokemon game per se)
Going by that pattern we're not going to get Black/White remakes until the Switch successor comes out, and usually a mainline Pokemon game takes a few years into a new Nintendo system's lifespan to come out. I wouldn't be surprised if Gen 10 is held off until 2026 so they can line it up with the franchise 30th anniversary.