I guess since everyone will know this imminently when the patch drops later today and beta is officially over, here are the list of upper star rarity requirements that will be live today:
REMINDER: You can still grandfather kingdom stars up until the point where the patch is pushed live later today, if you cannot reach the new requirements for the same star rarity under the new system.
6-Star
Own 12 kingdom troops
Level 10 kingdom troops to 20
Complete all 35 kingdom challenges
7-Star
Own 3 kingdom weapons
Fully trait 10 troops from the kingdom
Own 2 unique legendary troops from that kingdom
8-Star
Own 16 kingdom troops
Level 14 kingdom troops to 20
Fully upgrade 2 kingdom weapons
9-Star
Fully trait 16 kingdom troops
Own a pet from this kingdom (Not possible everywhere yet)
Unlock the Hero class associated with this kingdom (Not possible everywhere yet)
10-Star
Own 20 kingdom troops (Not currently possible anywhere)
Level 18 kingdom troops to 20
Own a base mythic rarity troop from this kingdom
11+ Stars
Unknown