Sorry, but how is anyone supposed to know that?
Firstly, we don't write the anime. Yes this is a database/ information site, but we can't tell you things no one knows or things that are physically impossible to find out. Anime leaks only really happen when the producers want to release information for publicity.
Secondly, Ash will get new Pokemon, so the screen time for his old Pokemon - with the exception of Pikachu - will greatly decrease. The only reason they'd bring and old Pokemon back, like Charizard, is to make the older fan base happy.
Thirdly, as explained in the Anime FAQ for anyone who wants it, the reason a lot of Ash's Pokemon don't evolve is because the lower stages are usually cuter and therefore more appealing to the anime's main target audience.
Additionally, there are some Pokemon that don't want to evolve, like Bulbasaur. As for Squirtle, it's in the Squirtle gang. It wouldn't make sense if it evolved. It was also bffs 4 lyf with Bulbasaur, and it would be more aesthetically appealing if both were kept at the same stage and therefore same size/ height. The exact same thing with Scraggy, since it's bffs with Iris' Axew.
If you really want to know if a Pokemon evolves, just have some patience and watch the anime for yourself.