Oh! It's not the dragon that roars as you are passing out of the Us room on the Nautiloid. It's just the shrieking imps. The dragon doesn't even roar anymore. How disappointing!
Yeah, I checked. US does talk and can be heard from the bottom deck. The dragon however no longer roars.
I wouldn't be surprised if his roar is simply bugged so the audio doesn't play, as a lot of things seem to be this patch.
For example the Zariel Tiefling's Searing Smite that you get at Level 3 no longer plays audio when targeting enemies. So probably just an audio bug, among plenty of many ^^
