"Delete Media Files From Disk" Where did Premiere delete them to? Can I get it back?

I was able to salvage it through sheer luck (turns out Dropbox was synced into that folder and they had a copy in their cache) but I'll grab a recovery utility for just in case this happens again! I've also learned my lesson regarding that button and won't be deleting any media files through Premiere, now that I know that's a thing Premiere can do

Not quite, what I did was check the button "Delete Media Files From Disk" within the offline popup. I didn't think Premiere was capable of deleting the actual files for the reasons you mentioned, it only ever seemed to care about Premiere's relationship to the file, not editing/deleting the file itself. I'm not even sure why anyone would want Premiere able to do that, seems easy enough to go delete the files yourself, and at least then they wind up in the Recycling Bin.

Luckily the folder the file was in was also hooked up to my Dropbox account, and Dropbox saved a copy so I was able to restore from Dropbox, but so far it's looking like Premiere would have cheerfully obliterated that file without recourse on its end. I guess I need to be careful not to check that button in the future, and to realize that Premiere is capable of leaving its domain and deleting or editing files elsewhere on my computer, which is lowkey scary but good to know I guess.