Earlier quoted context omitted.
Yes, if the keys are held in servers that they have access to then they would be able to decrypt the traffic and see what is happening. The whole point of e2e encryption is that only the 2 parties have the keys, Zoom are abusing this term and making people believe they are doing e2e
What makes you think they're abusing the term? Did you read their whitepaper? https://github.com/zoom/zoom-e2e-whitepaper
https://twitter.com/alexstamos/status/1268061792527241216
He did not say they can't monitor calls.
https://twitter.com/alexstamos/status/1268061795572314113
If they can enter the meeting, either they have to get confirmation from the host who would send the keys to the person entering the meeting or they already have the keys and can enter the meeting and decrypt the stream.