That way of excluding cameras always bothers me. What is a "professional camera" is a Canon 350D with a 55-250mm lens a "professional camera" or is a 1DX Mark II with a 40mm f/2.8 "Pancake Lens" a "professonal camera".
I have a hunch that you could very likely pass into a venue that excluded "professional cameras" if you were carrying the Canon 1DX Mark II with the Pancake mounted and be very lkely to be excluded with the Rebel and 55-250mm lens. BECAUSE THE 55-250mm IS PHYSICALLY LONGER THAN THE 40MM PANCAKE.
That said, if you were allowed to enter with the pancake mounted 1DX Mark II, you could just as easily be excluded the next time because of how the gate person interpreted that entirely vague "professional camera" regulation
And... telephoning in advance will not assure you of entrance. That entrance is entirely at the whim of the security guard...
The San Diego Poinsettia Bowl football game has a very reasonable regulation. You can bring in any camera you wish but, you are asked not to shoot during the actual play. You can shoot the pre-game, half-time, and post-game activities but not the play...