I suspect the argument in favor of preemption here will be made under the Federal Aviation Act of 1958 as it relates to passenger interference with crewmember duties, failure to comply with crewmember instructions and the authority of the flight crew to direct the removal of an unruly passenger.

With respect to the Airline Deregulation Act of 1978, the preemptive scope is, succinctly, any state-based claim which relates to the rates, routes and/or provision of services by the air carrier. You can probably craft an ADA preemption argument based on the passenger's attempt to secure an E+ seat without paying the required surcharge, but I believe the FAA preemption argument is stronger.

I have nothing to do with this case, just sharing my observation as an attorney.