To ForgeFed something similar happened when they were still on Github and the owner of the repo suddenly went AWOL. To this day that repo’s README is not updated with a pointer to the new location.
I haven’t checked this, but a simple solution - but with a certain extent of centralization to it - may be having e.g. a Codeberg organization where you have a team of people with highest privilege, and then do not use a custom domain name but the Codeberg Pages supplied domain, which can be e.g. fedeproxy.codeberg.eu