This is a quote from the EA help site
https://help.ea.com/au/help/the-sims/the-sims-4/events/#How-to-claim-rewards
All rewards earned through Gameplay Events are linked to your EA Account. If you uninstall The Sims 4, you’ll still have your rewards if you reinstall and log in with the same EA Account you earned them on.
Thanks for the information. But does that also mean if I uninstall the game and reinstall it, will the Ghoulish Guitar still be there, too?
I am not sure but I think that the Ghoulish Guitar is tied to your account and so it should be still there if you uninstall and reinstall.
