The thing here is that other animal species can act as a large...

The thing here is that other animal species can act as a large reservoir/incubator for the virus. It is possible for it to mutate there and jump back to humans, perhaps in a more severe form. Now, people don't come into contact with wild deer all that often, but there are people who interact with them, and they are hunted and eaten as well.

The question is what other species are infected, and how widespread is the virus in both domesticated species and wildlife. It has been shown that pigs can be infected in one study, although they are pretty resistant to it.

CDC: "cats and dogs, big cats in zoos or sanctuaries, gorillas in zoos, mink on farms, and a few other mammals can be infected with SARS-CoV-2"

we simply don't know enough about the topic, but it is potentially dangerous.


Related:
Our tech has been used in the past to experiment with detecting a pig virus.
https://hotcopper.com.au/threads/betaarterivirus-suid-1.5926557/