https://github.com/hooram/ownphotos/compare/dev...LibrePhoto...
I don't know if the original repo and LibrePhotos will permanently diverge (that appears to be the intention), but I like you am a bit confused at the necessity for a permanent fork and I'd like to know more too before committing to a version.
Maybe the two repo authors can come together and sync the projects since both are so closely related. Nonetheless, I hope there will be more information via a changelog or an outline with differences and intentions.
It's one of the more impressive projects I've seen to replace Google Photos so I hope there's a lot of transparency!
I think that's a terrible idea, disregarding the origins and removing an element of credit and attribution to the original authors. Be proud of where you came from, don't try to hide it.
Credit goes in the credits file, not polluting every interaction with the project.