I don’t think that will be the case. In my opinion real problem is not MM but playerbase structure (too small, not evenly spread across levels and arenas) plus boosts (speed one is biggest offender) which allows to cheat your way into higher arena where you don’t belong.
Maybe new MM will push some lower lvl players into lower arenas, but the rest will stay the same. you with lvl 27+ dinos are in the same arena that me with lvl 20-21. My kind of players is not the one who makes your matches frustrating, but if my place will be taken by someone else then who will it be you think?
I’ve said that on forums already many times - it’s the same situation all the way down to ruins. There having lvl 18-19 dinos I was getting players with lvl 20-24. Two arenas later it’s the same. I don’t judge those people, cause whatever reason there is they are where they are. Maybe they don’t care, maybe they are “carebears”, it doesn’t matter, but they are playing this game longer, have better dinos and we are in the same arena.
I know I sounds like all gloom and doom, but that’s what I think - small tweaks to MM won’t make arena less frustrating. It would require much bigger and less settled playerbase to have opponents where to choose from. Or there could happen something that would equalise current players chances in arena like sudden change of meta and nerfing all tyrants which would force long time players to leveling up some other dinos (that won’t happen) or slow power creep - this one actually happens, but is a slow one to make a difference.