Yes you can arrange for a gluten free cake at the Wave. I don't know which bakery they use for the gluten free cakes. At some restaurants they're now working with Babycakes but I think restaurants in some of the resorts are still working with their own chefs/bakeries to produce allergy cakes. You'll need to contact the appropriate cake hotline for the restaurant where you want it delivered. There's a cake thread on the restaurant board that has all the contact info in I think the first post of the thread. I only have experience with the Babycakes cakes and we really enjoyed them.
ETA: I was assuming you meant the kind of cake that people order and pay for. If you're just asking if there'll be a gluten free dessert then yes there will be options but it won't necessarily be cake. There should be brownies or cookies that can be doctored up plus I think they may have some kind of sorbet or mousse trio that's gluten free but I really don't know for sure.