Speaking of evolution leaks, I found this on Tumblr:
My thoughts on this:
The Rowlet evo becoming an archer is definitely an odd concept but one that could be fun, the main issue will come down to if the massive Rowlet fanbase finds it ugly or not. It's not a bad design and all, but those sunglasses it seems to be wearing do look out of place. Plus, the fact Rowlet shoots leaves out of its wings that eventually become arrows looks like something that makes sense and transitions well.
The Litten evo is biped, which would continue the disturbing trend of Fire starters always going bipedal when they evolve but also has that tiger look that's all been theorized, also that muscular body could suggest Fire/Fighting, so that means could Litten decline to Tepig levels of unpopularity? It is definitely a concerning time for Litten fans with this, especially if they hate Fire/Fighting starters becoming a thing again.
The Popplio evo is... a mermaid? That is not what I'd expect a little sea lion to evolve into, but then again I know how much Dewgong's tail reminds me of a mermaid and the speculated Water/Fairy evo for Popplio (Water/Psychic could also fit). If this is the case, Popplio seems like the "feminine" starter that everyone will want to soft-reset for a female, a la fellow feminine starters Fennekin and Chikorita.
I did notice Japanese text which I remember we had Japanese text when concept art of previous starters were shown (I know we had art of the Unova starters that was concept art with Japanese text written in parts, as description) so it does look suspicious. There is also the presence of a red "Confidential" label which was also present on a concept art piece of Noivern.
Edit: The supposed Katakana text of these final evos appear to be called "Fukurou" (Rowlet evo), "Tora" (Litten evo) and "Ashike" (Popplio evo)