Of all the things I can think of to fib to you about, this would not be one of them 🤨
Your provider (who is not AOT but a third party) is being somewhat pedantic. “Fast track services” are alive and well, as evinced by the screengrab from the AOT app today, and also the service I booked via my hotel last week. There was a specific gate that was literally called “Fast Track” which is closed, but you can still be met by a “butler” brought to a special express lane which could be (as in my case last week) a separate set of lanes that are usually for diplomatic use and also made available for fast track passengers, or perhaps the regular priority lanes that you wouldn’t otherwise get access to unless you are senior, disabled, with babes in arms, or a monk. I suspect that third party service providers may get access to better express lanes the more they pay at the airport.