If I create some file using Path.GetTempPath() - does it automatically get deleted at some stage, or is it up to me to delete it?
Starting with Windows 10, the answer is posibly yes - depending on the machine configuration and the amount of free space on the drive hosting the TEMP folder.
Specifically, Storage Sense can arbitrarily delete files from the TEMP folder (I found that out the hard way) if enabled by the user. And from what I can tell, it will self-enable on low disk space.