No. It’s not just a dumb radio signal like Homelink. The way MyQ should work is thru the MyQ API. The API has a command for “open door” and a separate command for “close door”. Even if the car resends the open door command to a door that is already open, the door should not close because the MyQ device in your garage knows the state of the door before it sends the dumb radio signal.It is the signal that Tesla sends after all, which is just dumb trigger signal just like from the garage clicker. I am not 100% sure if MyQ sends dedicated signal for open and close, but my MyQ App doesn't have that kind of dedicated button. It is just one button on the screen that opens and closes the garage door.
The reason the MyQ app has a single button is because it knows whether the door is open or closed and allows you to do the opposite thru a single button but you see that the app knows the state of the door and how long it's been in that state.
I have Apple shortcuts set up that work this same way thru MyQ. If I click the open door MyQ shortcut multiple times, it only opens the door once and the subsequent commands are ignored.
All that being said, I have not tried MyQ to verify but I would be very surprised if it worked differently than I suspect.
EDIT.... curiosity got the best of me. There's a 30-day MyQ trial so I enabled it.
As you can see here, the status on the upper left knows the door is already open and only allows me to send a Close Garage command.
The subtle difference being that there is a Open Garage and Close Garage command with MyQ. Where Homelink was a true dumb command that would activate within range regardless of the state of the door. Hence the reason the Homelink button on the Tesla UI says "Activate" and does not say "Open" or "Close".