I'll start this thread with a simple question, which would you like to see most? Pheasants, guineafowl, turkeys, grouse, partridges, curassows, quails? Or maybe something else.
I want to see a basic wild turkey the most. If it has appropriate interspecies enrichment with both domestic and wild animals, it can stand in for its domestic counterpart and add an iconic bird for North America. To me, it is one of the most useful birds they could add. On the large, domestic-ish fowl front, a helmeted guineafowl would also be nice to finish off that niche.
For the many wild Asian pheasants, I want to see the golden pheasant the most. It is very beautiful and common in zoos. One that shares a range with it and has contrasting colors would be nice for mixed exhibits. I like the idea of a silver pheasant to go with the golden one, but the morphologically similar Lady Amherst's pheasant would also do brilliantly. I could almost picture Frontier pulling a Grasslands and giving us the golden and LA pheasant as a two for one. After that, I'd be pretty happy with the vanilla roster's pheasant lineup. There are other options like the Argus, Reeves's, Common pheasant, and Himalayan monal that would be nice for mods, but I think 2 East Asian pheasants would be enough for me and most people who don't use mods. Getting the domestic chicken has nullified my interest in the red junglefowl, as much as I like its classic chicken colors.
For other species, I don't think anything is necessary. A currasow would be super cool for tropical houses, but it seems like such an oddball that I don't expect it. I think prairie chickens are really cool, and North American grouse species are ok. Neither strikes me as an exceptional, likely pick for PZ, though. I think the capercaillie could be ok, but the mallard and pelican are much more useful and more popular among European birds. Assuming we get both, Europe would have 4-5 birds, depending on whether you count the chicken. I would like to see other regions get a few more before I'd get remotely excited about the white stork and capercaillie, too.
To summarize, I really want the turkey, ~2 pheasants for East Asia, maybe a guineafowl, and am hopeful for but not expecting a currasow. Everything else, assuming a balanced roster, would be a bonus. Pheasants are cool.