I have accepted the proposed divisions as nominated ("Gundam 00 & Anno Domini Gundam" and "Gundam SEED & Cosmic Era Gundam") because they seem sensible and fit with what the fandom's wiki tells me are essentially completely different timelines, but I am happy to rename them if there are strong arguments for it. These seem to have been sorted into sensible-looking places in the tag set, which to be honest I'm a bit confused by; I'm nowhere near as fandom-adjacent to Gundam as I am to Tolkien, but it has tagging issues visible from space.

Thank you for leaving the tags as I nominated them. You are indeed correct that the Gundam section has tagging issues visible from space!

Have they recently been resolved?

No, and they won't be. Despite multiple requests over multiple years to use more accurate names for top level Gundam sub-franchises, use correct fandom names instead of shorthand, and use the same criteria between timelines to distinguish separate top-level Gundam fandoms, AO3's Gundam tag wranglers are unfortunately unwilling and/or unable to make any corrections or changes.