Are placement matches going to be changed/reworked to be less easily abused?

There are three major problems:

1. Placements don't seem to take last season's MMR into account. A boosted Diamond V player who maintained 0 LP Diamond V with 42% win rate will be given the same placements as a Diamond V player with 60% win rate.

2. Your placement starting point doesn't seem to decay. If I do my placements at the end of the season, I will place into the same tier I would have if I had done them at the start of the season, regardless of how much MMR has inflated during the season.

3. You can duo queue on a new account to ensure you get placed in high Platinum, without needing a high win rate. This makes boosting insanely easy. Platinum I to Diamond V is saturated by extremely toxic Chinese players who are doing this; you encounter one or two of them in almost every game.

The first point is problematic in that it ensures Platinum remains saturated by boosted players. It's extremely hard to drop out, because even if you're playing in a game well above your skill level, you'll still be carried often enough to hold 4X% win rate, and it will take hundreds of games before you drop to an appropriate level.

The second point actively punishes players who want to maintain their rank, and instead promotes not playing until the end of the season, especially for Diamond players. I want to sit at Diamond V until the end of the season, but I don't want to play more than I have to, because the majority of games at this MMR are full of incredibly toxic or boosted players, and I don't enjoy the state of balance.

I stopped playing for a few months after reaching Diamond V at the start of the season and decayed to Platinum IV; after coming back, MMR inflation put my MMR around Platinum III, and I had to play another 60-70 games to get back to Diamond V. It would have been better for me to just not play at all until the season was ending, as decay doesn't set in until after placements. Because I played early, I have to consistently continue playing, or MMR will inflate around me.

The third point is a major issue that makes boosting new accounts to Diamond trivial, see the first point. It also contributes to the number of extremely toxic players, because they aren't worried about getting banned; they can just grab a new account, duo with a high Diamond friend through placements, and be back to Diamond on their new level 30 account in 50-60 games, without even having to maintain a high win rate.

This system is pretty terrible and probably should have been fixed in earlier seasons.