I agree with your points but still don't see why the costs associated with someone working as an animal caretaker would rise any faster than the costs associated with someone working as a landscaper, Disney transportation worker, lifeguard, front desk staff, security worker, restaurant manager, etc. The vast majority of the animal care staff are not veterinarians. They will be people doing jobs like putting out food, keeping an eye on the animals and daily cleaning and maintenance of the savanna.
Also, in regards to veterinary care, it's not clear exactly what AKV owners will be responsible for. Do all of the animals at AKL/AKV receive an annual physical? I could see that being included as part of the cost of caring for the animals but that cost would be incurred once/year/animal. But what happens if one of the animals at AKL/AKV becomes seriously ill or suffers a serious injury? If an animal at AKL/V gets cancer, will AKV owners be responsible for the costs of surgery and cancer treatment? I somehow don't think that will be our responsibility because we don't own the animals but I don't know that for sure. Assuming that just the routine medical costs are passed on, and given how many owners will be sharing that cost, I don't see it adding a huge sum to the dues.
The cost of animal care is an expense the other
DVC resorts do not have, but then again, I expect AKV will have lower landscaping and transportation costs than SSR, will not be paying any boat transportation costs unlike BCV, BWV, OKW, SSR and VWL, will not have the Boardwalk entertainment expenses of BWV, will probably have lower pool expenses than BCV, etc.