I'm not 100% sure how to post a reply but I did click on the "View Game Replay" button of a recently completed game. The end of game summary states that both expansions are enabled and the faction selection was random. Here is the link (hopefully):
https://boardgamearena.com/gamereview?table=873108174
The first move in the replay just states, "Player order has been rearranged". It says nothing of the how the factions were assigned. The expansions were enabled but somehow randomly none of the 4 players were assigned an expansion faction? I remember that someone in the game commented on it.
I'm currently in two games with both expansions enabled. In one the factions are random, in another (that I started) players choose factions. I didn't see any of the expansion factions when the game started, there are no expansion factions in that game - it's possible that no one else chose them. In the random game it's also possible that non of the expansion factions were selected but it's a little suspect that in 2 games all 8 factions were the older ones and I haven't seen a single new one.
Do I need to be a premium member of BGA or have been on the beta testing to see the new factions?