LKE towards TOP-5, page-54

What you wrote is exclusionary against a certain group of people, i.e. directors.

Just replace the word "directors" with any other group of people, and you will understand why it is exclusionary what you wrote.
If you had put "women" e.g. instead of "directors", your message would've been:

"Further supports my opinion that women should not be tweeting/posting on social media”.

Do you understand why what you wrote is exclusionary against a certain group of people?

Directors are also humans like you. They should be able to post on social media. They should obey the laws, and they should comply with the rules of the specific medium, but provided all the above is true, it is exclusionary to say that they should not be tweeting/posting on social media.