In fairness, the release notes to the beta (which were publicly available this time) did note the following
- When you download the build, you may have to reinstall the whole sim if you do not have your core files saved on a custom path. This is expected and a part of the test.
So while the timing is a bit unexpected, the outcome shouldn’t be. As someone who followed the testing notes, this was an easy 1.5 gb store download for me and simply pointing the sim back to where the files are installed on a separate drive.