I have insider information on the gen 4 remakes.

The titles of the gen 4 remakes will be Chrono Diamond and Cosmic Pearl. Dialga amd Palkia will gain form changes similar to primal reversion however these will be more like their ascended forms, dialga will become chrono dialga and palkia will become cosmic palkia, arceus and giratina also gain new forms but I wont go into those now. The sinnoh underground has been remade and contains various different underground biomes where you can find a new type of item called an unstable genome which will allow you to turn any pokemon that has a regional varient into that variant (e.g. ponyta into galarian ponyta) and there are a few new varents exclusive to the sinnoh region that you can now discover. The post game has 2 delta episodes where you explore the distortion in the forst one and a new dimension found at sky pillar where arceus calls home. Both mega evolution and dynamax/gigantamax will be in the gen 4 remakes, however they will be game exclusive with Chrono Diamond having megas and Cosmic Pearl having dmax/gmax

Thats it for now