I'd rather see the Tellius games get full remakes than an hd remaster collection. I'd also like to see at least FE4-6 get remakes first. That way only Marth's second story (FE3 book 2 / FE12) is left without an official English version.
If IntSys was more willing, I think there's room for both. A Tellius remake is probably closer to 10-15 years away, so I don't see the problem with an HD remaster in the meantime.
There were two years between SD (2008) and New Mystery (2010), seven between New Mystery (2010) and Echoes (2017), and if FE 4 Remake does release this year, it'll be another seven years in-between remake releases. Even if IntSys and Nintendo release a Fire Emblem mainline or spin-off game every year for the next roughly ten years, and assuming we're going in chronological order, it's still going to take time. Pulling out the hypothetical timetable:
2024 - Genealogy Remake
2025 - Genealogy Warriors
2026 - Thracia Remake/Original Game
2027 - Warriors 2
2028 - Original Game
2029 - New Remake (Elibe)
2030 - New Spin-off + 40th Anniversary (Possibly another Shadow Dragon remake)
2031 - N/A
2032 - Original Game (on Switch 2 Successor)
2033 - Magvel Remake (reusing 2032's game's assets)
2034 - New Spin-off's sequel
2035 - Tellius Duology & 30 Year Anniversary
As you can see, we've got TIME. I'd say that either in 2025 or 2027 (preferably the latter), do a Tellius Collection that somehow gives you bonus items in either Warriors game, not unlike how Three Houses' data gives you more Owl Feathers in Three Hopes.