The interesting thing about that theory is: I don't know how to assess which of those two scenarios is more likely.
Do we still get to blame the lab for a leak?
There are no discovered bat populations in the Wuhan region with a SARS-COV2 ancestor, that's more likely.
That the only source of bats infected with a SARS-COV2 relative is in the Yunnan province, that's pretty unlikely.