My addons persisted through a reinstall?

On PC playing via Steam. I saved my Packages folder (that contains the Community folder with addons) to a different directory so I could copy it back after reinstalling the game.

I uninstalled the game via Steam, and even doubled checked that the original Packages folder was deleted (it was, I couldn't get to it). I restarted my PC, then installed MSFS 2024 again via Steam. Booted it up to do a quick test flight, then closed it.

Now I go to copy my Packages folder back but it's already there, with the Community folder and all the addons I had previously.

Does reinstalling even preserve your 3rd party addons or am I missing something here?