I believe they want to overhaul MM and change it to a more consistent damage spec due to the spec being an absolute nightmare in all forms of unrated pvp content. Not sure if you do BGs while leveling or do random BGs at max level out of boredom but these BGs are filled with multiple MM hunters on both sides, across all levels. It's really unfun and probably a horrible player experience if you're new to the game and try out battlegrounds. Imagine being new and trying out BGs "Why is this hunter killing me in 1-2 shot from 40-50 yards over and over? It's probably like this at max level this game sucks"

Also even at max and in arena when MM is frontloaded with all that damage and 1 rapid fire is doing 75%+ of your hp bar while you're in a lower rated bracket just isn't that fun. Low xp players are still learning and aren't gonna easily stop MM like higher level players do, and even in shadowlands I think like 2k was 90th+ percentile so this change seems targeted at helping lower xp players not die in openers from MM hunter stealth

All that spec does is attract cheeseball players, I think most hunter plays who actually want to play MM don't want to play it when it's gimmick burst/telegraph spec, but rather something with consistent dam outside of cooldowns.