@Taransworld found that the last banner (i.e. thunderbolt) has the same id than Apocalypse’s kingdom (each kingdom has a number).
I guess that the next kingdom will use the 1st banner (i.e. eye for a beholder kingdom).
We only saw a part of the map and so, only two new kingdoms. Kingdoms ofthe imps and apocalypse are surely in another part of the map that we didn’t see during the stream.
If you check previous posts, banners for all kingdoms have been found.