Do you believe that Musk is not going to push his cars on Twitter? Seems to me that you have access to a fairly large audience on there.
Musk (who is definitely the beneficial owner of Twitter and probably of Tesla too) is providing "free" consulting service of Tesla employees for Twitter -> without an invoice and without tax. (or maybe there will be an invoice?)
In EU that should be taxed (and also invoiced) - with similar prices as a consulting provided by a consulting company that does code reviews. The tax office is interested most in the missing tax of course.
There’s very little here to make any kind of judgement from.
Perhaps they were being paid for some private work outside of their employment. Maybe there’s some kind of arrangement in place to cover the costs of their time. From the outside we simply don’t know.
That is a great idea, running ads in Tesla cars. They can introduce a monthly subscription to opt out of the ads.