Setting: Auto Remove Non user Reactions

This feature would be a setting on the server, under server settings. 

once toggled it will remove there reactions of all people who are no long in the server.
it will periodically do this when a user leaves the server and scan the discord for all reaction they have made and remove them.

This feature is needed for large discord where we use, reaction bots to gather information we need to help run the discord, for example active polls and sign ups