When you see something like this, the board wanted him out anyways. This was the perfect opportunity. If Elon Musk has an affair with an employee the Tesla Board will release a solemnly worded statement and say that he’s being required to attend certain trainings and produce certain mea culpas.
There are such rules in place for Elon Musk specifically as a result of a settlement with the SEC, but he ignores them.
(The rule he's ignoring is not that he's not allowed to tweet about Tesla from his personal accout, it's that he has to have such tweets vetted by a lawyer.)