There is an interesting discussion about bats, pangolins, and SARS-CoV-2 in the Nature Communications paper "Evidence for SARS-CoV-2 related coronaviruses circulating in bats and pangolins in Southeast Asia" [1].
The paper is also discussed in some detail on TWiV 722 [2]. The discussion starts at about 00:19:20.
@johncarlosbaez There was a interesting episode of TWiV (TWiV 714) that discussed state-of-the-art knowledge about SARS-CoV-2 spike protein cleavage and fusion. I wrote a few notes about the episode here: https://davidmeyer.github.io/biology/fusion.pdf.