Really should stop requiring your players to have to rebuy the game or forcing them to have to subscribe to the patreon just to be able to play the most up-to-date version of the game. Especially if they had already spent the money on a prior version. Otherwise, updates like these would be amazing, and I wouldn't mind having to go through and reset my save just to experience everything.
I created a feature request on their Github. Maybe if enough people pile onto it it will get addressed. https://github.com/itchio/itch.io/issues/1775