I saw somewhere on Twitter, possibly as a reply to Scott Helme, that they possibly added these URLs to their CSP because they were getting errors in their CSP logs from machines that had adware/malware loaded. Can't find the tweet though, so maybe it wasn't him (but I'm reasonably sure it was a discussion of CSP, ReportURI, and the fact the CSP changes depending on logged in/out of zoom's site).
Pretty bad solution if that was indeed the case.