A steward has a finite number of hours and a contract they actually know. They do not need your assistant's reading of labor law.
Timeline, then the question
What was said, who was in the room, the date, what you already signed or refused. Then: what do I do next, or will you come to the meeting on Thursday.
Facts and guesses apart. "The meeting was at 14:00" is a fact. "They are building a file" is a guess unless someone said that.
Do not send the polished vent
The model will make you sound lawyerly. Cut it back to words you would say at the locker. You approve the note. If you would not sign it, do not send it.
This is not a filing
RelayLink is a letter and a thread. It is not a grievance system. If they tell you to file, you file where the contract says.
They do not need an account. Email is enough. If you work together often, you can invite them later. The first question does not have to wait.