Do you think aliens in ufos have visited Earth? (And all things UFO)

I don't really agree that this has any dire consequences for Catholic/Christian doctrine. Just like with the Copernican revolution or evolution, Christian theology would eventually morph/adapt (despite its more rigid sects being left behind and eventually dying off). The Bible itself is full of that sort of thing. Maybe that's all for a different thread.
Yes, religion has a habit of moving the goalposts whenever something contrary to their belief is proven or provided. I'm thinking that the line would be "God created the universe and inhabited it with beings after his image, but his image is always changing and is perceived differently by many.".
That's exactly what would happen...but it would be ironic if our alien overlords sent missionaries to convert the human population to their religion(s).
They may feel compelled to "save the heathens". We may all fall victim to their version of smallpox.