Altering photo dates within shared albums

I'm trying to understand what happens to photos once I add them to a shared album.

I've been working on a long-term project of re-scanning thousands of historical photos. I scan them into Photos, edit and clean them up, then meta tag them with titles and correct dates. Then I share them to a shared library.

My understanding is that once I share them to the shared library, they are shared in that exact state, in other words, if I make any further edits to the local photos (graphically or metatags) the version in the shared library does NOT get those updates.

I've been browsing my shared library and have found that I made some date errors in the meta tagging, so the shared library is showing photos in the wrong order. What's the easiest way to correct this?

Can I correct meta tagging of the photos in the shared folder and will it automatically update my local copies? Or is there a way to correct the local copies and have the shared versions inherit those updates?

I'm hoping NOT to have to unshare photos, fix their dates, then re-share them, because there's just so many to do, and the sorting makes the task near impossible since there are thousands of them and they're in all kinds of crazy orders.