The result is a significant performance improvement in gaming across a variety of Zen 4 and Zen 5 desktop Ryzen CPUs, including the popular 7800X3D chip. “Users will need to look for KB5041587 under Windows update > Advanced options > Optional updates,” says AMD in a statement to Wccftech. “We expect the performance uplift to be very similar between 24H2 and 23H2 with KB5041587 installed.”
So...
The fastest gaming chip that is cheaper than everything close to it...
The X3D's just have ridiculously overbuilt caches. That's the main thing (that I'm aware of) that makes them so fast with games while still being cheap.
AMD just put more of that than Windows could handle to max out speed in games.
So I'm assuming (and may be wrong) that the windows optimization is just updating it so that it could plan for those insane caches and take full advantage of it.
Scheduler improvements. These improvements will be standard in an upcoming stable release, but with the launch of zen 5, amd worked with microsoft to get an optional patch released. Wendell with level1techs has some good content on the subject if you want to learn more.