Well, it doesn't look like it's gonna happen in 2024, because the Pokemon Presents didn't even mention a Johto remake once.
I have a slither of hope that one happens soon (maybe at some other point of the 2020s for like the Switch 2), and it probably should.
Johto has also gone the longest without a remake. HGSS came out way back in 2010 for the Nintendo DS. All Unova games that have ever been released were also for the Nintendo DS. I've played games that take place in every Pokemon region in the main series. So, if they were to make Johto and Unova remakes soon, the developers could give today's kids a chance to play Pokemon games that take place in every single region as well.
I also remember when Johto has also gone the longest without a remake before HGSS came out, so, you never know.