It is disappointing. We have been through several updates since the new file recovery system was introduced and it sounds like this behavior of erasing the backup before confirming a successful save of a recovered file is still with us. I have not had an un-savable loop with a recovered file for a while so I didn’t know if this was fixed or not, wish I could bump this issue to get fixed in a future update.
The safeguards against this are to save often manually or keep autosave engaged with a reasonable time period so you are not relying on the recovery system. If you must recover a file, ignore the SketchUp recovery system and navigate directly to the recovered files folder in your system, make a copy of the file you wish to recover first so you can place it back in the recovered folder if/when the original gets deleted. File paths are here…
Incidentally, navigating to the source folder is also the only way I know of clearing recovered files so they don’t persist in perpetuity on the welcome screen. Too bad this pathway is not included in the SketchUp>preferences>files page