I just had a panic moment, all builds of a vr project I made for my masters degree started crashing with this update, Avatar support in Unity broke (had missing entrypoint errors). I need to record a video of the project in use by tomorrow night for the final submission.
I turned off the testing channel and rebooted. I got a forced firmware update (second one tonight) and now everything works fine.
(Nothing else was broken for me, I could start Beat Saber fine. Dash did tell me that the last time I played Windlands 2 and Google Earth was 49 years ago though. Pretty sure it wasn't that long ago...)