SC2 Pulse has a new tool, where you can track player MMR Performance by patch.
Sc2 Pulse has a new tool you can use to track player trends using their database.
I'm going to copy paste their summary of changes from their discord. If you're interested in playing with it, here is the tool!
https://sc2-pulse.github.io/performance-by-patch/
Top ladder players, up to 1500 teams.
Max MMR, avg MMR, trend, and confidence per team.
Race summary.
A wide variety of filters.
The player section is good, it's basically slope + SE and SNR, should be pretty accurate. The summary section is just a template. It provides many filters, but I'm not good enough at stats to make an opinionated default view. Currently it just loads stuff using conservative filters.