As far as I know, emby "only" uses the tag-field "year".
My suggestion is integrate the "Original release date" (maybe in brackets behind the date). lots of albums are remastered and I always get confused, though emby does not show the original date.
I've PM'd some sample tracks to @Luke
Some clearer thought on how this should work, imo.
For studio albums, emby should prioritize originalyear or originaldate tags in both album and song contexts.
For compilation albums, such as a greatest hits album, using originalyear or originaldate tags in song context is certainly correct. MusicBrainz almost always has the wrong info in this case, but I've fixed mine (or nearly so). Also, I'm willing to share my data file of compilation yea