I wouldn't be against it but I'd much rather have MOAR Ravenloft! But there are plenty of jungle environments in Xendrik they could more fully explore. Some of our adventures already take place there (Ruins of Threnal, Stormcleave Outpost, Faithful Departed) but there is more than enough room for more. I'm not sure where Redwillow's Ruins are located but they also fit in Xendrik and its giant ruins. Certainly, they could fit in new(er) civilizations of Yuanti or Lizardfolk and new mobs like Bulette, recolored panthers to be jaguars, constrictors, maybe couatl, maybe some fungus mobs?