No need to uninstall. If you simply download the installer from here: https://overheadgames.com/epic-character-generator/ – it should automatically pick up the last installation location, and simply by clicking Next on each step you should have your executable repaired, and everything else will remain as you used to have them before the new update came out.
The reason you saw this happening now with the new character is that it was released at the same time the new update went live. If it were a simple update without a new character you would’ve experienced the same, unfortunately.
On a related note, Avast got back to me and whitelisted the executable already. Norton is still pending for over a week now.