I agree, but I think interfering with the communication channel is the wrong response. To me it feels like, "We don't like what Trump is saying, so we should stop letting people see it." Realistically that isn't going to make Trump go away or change his policies or teach him a lesson because he can just as easily give a press release, give a live speech, hold a rally, call into the news, etc. It won't change the message, just the medium.
Looking at it another way, Facebook employees should have the same responses available to them as everybody else. If they don't like what Trump said, they should reply to his post and tell him, go out and protest, or whatever. But what they shouldn't do is force their opinion on everybody else.
If the employees are dissatisfied with the direction of their company they are free to voice their dissatisfaction and ask for a change.
Personally I don't participate in any of those platforms, so I don't have a stake in any of it.
I do work in the larger publishing sphere, though, and I can assure you I would not appreciate being told I would be forced to run a regular column for an authority figure spewing misinformation and vitriol.