If you say something ML thinks is wrong in Teams, you can be fired (at will).
If you say something to your colleague via Whatsapp, the only scenario it can be used against you is if you commit an actual crime with reasonable evidence, they subpoena the records, and FB will be willing to go on record to the entire world as lying about Whatsapp E2EE, all in the name of putting you behind bars.
(Also, maybe we can imagine that products actually do what they do and it is not normal to fear lies and nefarious agenda behind every offering?)
Maybe the implication is that it will leak info to your employer, but I think this is more like a general statement; one that is likely an attempt to discuss why we still put our conversations into the hands of large companies with potentially unknown motives; and the questionable state of using "end-to-end" where one entity controls the network, access to the network and both ends of the exchange.
2) Why not use something you can host yourself
to which a reasonable reply is: network effects; I already have signal/whatsapp/telegram and I do not worry about them sending information to my employer.
Unless your employer is facebook, then I think that's a perfectly legitimate rebuttal, but one nobody is making.
In fact, people would rather argue that signal/whatsapp is the best privacy platform in the universe due to e2ee!
If you say something to your colleague via Whatsapp, the only scenario it can be used against you is if you commit an actual crime with reasonable evidence, they subpoena the records, and FB will be willing to go on record to the entire world as lying about Whatsapp E2EE, all in the name of putting you behind bars.
(Also, maybe we can imagine that products actually do what they do and it is not normal to fear lies and nefarious agenda behind every offering?)