You're right, that's a fair point. I wouldn't be surprised if WotC had avoided "Romani" because it felt like a demonym which wouldn't exist in their universe. :/

Are there any great substitute terms which focus on the lifestyle commonly associated with the Romani? "Nomadic" (or "nomads") is associated more with peoples who live away from civilization; "travelers" is a little weak, as it can imply a temporary activity.

Vagabond, Wanderer, Wayfarer, Rover, Roamer, Drifter