These bats are said to have come from a remote area in China. I don't know how hard anyone looked for more of them, it sounds a bit dangerous to me. But bats are known to harbor corona viruses. Most of this stuff to me is inference, and opinion, not evidence based facts, because the Chinese haven't been very forthcoming.
I think virologists SHOULD be able to assess whether this was modified or not, and their balance of opinion seems to be it was not.