Comment by snailmailman

They may not say "turn off bitlocker", but people definitely recommend backing up the recovery keys, and windows allows you to back up the key to microsoft because they know people won't actually back them up. Not sure if that happens by default, but they provide a variety of options for the recovery keys because there is definitely a non-zero chance you need them. There were several stories of this happening with the windows 10->11 upgrade push, where people were auto-updated and then scrambling to decrypt their hard drives.