I don't use cloud backup on a PC but I doubt that backup data being 'in the cloud' - i.e on a remote file server as opposed to being on a local disk - makes any difference at all.

The program* making the backup, and restoring the data, may be affected, depending on what features it has. That program might be part of the OS, such as Win 10's 'File History' facility, or a separate program such as Aomei Backupper (both of which I use). If I were upgrading to Win 11 I'd check whether those still worked, and whether the old backups are restorable.

* or 'app' as Windows now likes to call them