"happen to live in islands" and comparing island fauna to burrowing animals, wow, as a passionate person about insular fauna this is painful to read lol
Just so you are aware, islands comprise one of the most biodiverse regions on the planet and are a global paradigm of evolution and conservation, and their definition is not "vague" at all. Islands are unique environments with unique wildlife, insular animals don't "happen" to live on them, they are are result of a miraculous series of events that lead into organisms reaching these isolated environments and evolving in strange, unique ways over thousands or millions of years. Moreover, islands are incredibly fragile and are one if not the most clear examples of how humans affect ecosystems and how important conservation is. By all accounts, an island pack would be a really good idea that aligns perfectly with what Planet Zoo is about (also, would add banger species like kiwis).
I know many people consider it a "meme" pack because people speculated it from muh lord howe island stick insect leak but regardless it would be a fantastic pack to have, regardless if it follows the "-lands" theming or not.