“You can work here and say things that will harm us, but you can’t accept payment to say things that will harm us.” Feels like a very reasonable position to me.
If they were simply not allowed to take payment for that testimony, the article and title should reflect that, regardless if such a policy is also wrong.
And I would have liked for the article to elaborate more on this barring. What would happen if they testified anyway, if they did or did not get paid for it, etc.. It is after all the central issue of the article, and that they leave it so vague is either incompetence or deception.