I doubt they'll remove leveling, it's been a baked in thing with these betas for about as long as Pvz3 has existed, give or take anywhom.
It would be nice for it to be removed, but in that case a lot of balancing would need to be taken as a lot of plants are straight up better than others (sun seed is better than sun tower in sun production and costs a lot less, Umbrella and Jumbrella just being wallnuts and leading to not needing to use like, any of the other umbrella fusions due to how tanky and strong the zombies get).
(Yes I know the fusion fan-game has the same issue, but I'd rather this game actually make every plant usable).
If they really want it in, just add caps to such for each issue (issue 1 is level 5, issue 2 is level 10, so on so on) then give each issue proper stage design, pacing and story, allowing for less spammy stage design!
I said plant leveling, not plant evolutions
