This is what the Act says.
14 Owners’ attendance at executive committee meetings
An owner or, where that person is a corporation, any company nominee of the corporation is entitled to attend a meeting of the executive committee but may not address the meeting unless authorised by resolution of the executive committee.
On the question of whether or not you are allowed to speak, any owner or representative at an executive committee meeting can “address the meeting” with the permission of the EC. How do you get permission?
You stand up and say “Point of order: May I speak on this matter …” They then should take a vote and undoubtedly refuse to let you speak, at which point you ask for it to be minuted that your request was refused.
However, I would argue that they can’t make a blanket, pre-emptive ruling that you or anyone else may not speak as that countermands the provisions of the Act which allows you to “address” the meeting under specific circumstances.
Speaking at the meeting is different from addressing it. If someone was telling lies about me in a meeting, they’d have to carry me from the room to stop me putting them right with a couple of choice phrases.