Well when they update that 20 year old book into 5e and will have to see how they describe them then.
Yes, if and when WotC get around to updating them, we'll see what they do. However, the point is that it's not the OP's assumption that they're based on the Roma - it's a feature of the lore as it currently stands.
Lastly, last I checked the Vistani are the protagonists. (Which are described as gypsy-like)
The OP was talking about the AL adventure DDAL4-1, which I presume is set in the Forgotten Realms, rather than the current "Curse of Strahd" adventure in Ravenloft. Which probably explains why it's the FR version who feature rather than the RL ones.