It’s finally here!
My stats will take a long while to be available though. Looks like new changes are introduced here for how each Delve room is picked, so average Multiplier is no longer possible with the old formula.
Up untill now, I think I see some locked 2 Ocean theme and 1 Snake theme here, so the pool room is much smaller. Any confirmation on that, @Saltypatra?
Edit : It’s done! 
On average, it’s on par with Silver Necropolis, but could be better or worse depending on that 2 Ocean Legendary rooms. Could be a Farming Faction if you don’t have one already.
Overall, stats average on just 3 and 5 rooms are too small of a data size, making it less reliable.