I considered it when I was thinking of an avian DLC. I'm personally on the fence and it's hard to predict what Frontier will choose (if they even give us birds and if they even give some in exhibits). So far they have preferred to have animals for exhibits that don't move so much (which is also why we don't have exhibit mammals). Space-wise I think it's an option, as most zoos don't have them in aviaries much bigger than 4x4x4 anyways, but that doesn't mean it will happen. Planet Zoo is infamous for unrealistic space requirements, so I personally would add the kookaburra as a habitat species and save the exhibits for smaller animals like cockatiels, budgies and zebrafinches.