The Follow Me doesn't have a state variable associated with it, since it's a Parking service like a Marshaller or a Docking system, not an Assistance service like all the other vehicles, which gets states variable handled automatically. But we could probably add such feature to it.
However, it won't be possible to get the parking name, because L: variables can't be used to share strings, this would require a way more complex interaction between GSX and another add-on using Simconnect custom client data areas, using C++/C#
Yes, we could share just the parking Index, which is an integer number but then, you'll have to read the AFCAD file of the scenery to know its name, basically duplicating what GSX does with its own airport cache.
What we *might* do, could be setting the Lat/Lon coordinates of the currently selected gate (or runway start), since they are float numbers, so they can be easily shared using L: variables. Would that be useful ?