Hmmm? I'd tend to agree with them up there ^^^^. Ask the authority having jurisdiction.
By that definition
my condo does not allow any grill with open flame
all of my smokers qualify because the flame is inside the firebox, and not out in the open. That also would "go" for any offset type of a smoker.
Mostly what that rules out would be anything gas-fired (or even charcoal) without a lid.
In most pellet grills, there is more of a smoldering than a flame and the ignighter is usually electric.
I think I'd ask and get specific answers. I do know of people that got their Big Green Eggs approved because the fire isn't flaming and the cooking is done with the lid closed.
Good luck with your quest.