https://classic.wowhead.com/guides/classic-wow-stats-and-attributes-overview
https://classic.wowhead.com/news=291443/itemization-in-wow-classic-items-to-use-1-12-versions
Only info i could find on how stats and things will work when they bring it out .
https://classic.wowhead.com/
updates all the time on there and forums
https://eu.forums.blizzard.com/en/wow/groups/blizzard-tracker/activity/posts?category_id=235