yes MyTraffic X is based on real schedules
If it's *really* based on real world schedule, then you can hardly say it's an "invasion" of SAS but, if it's *really* based on real schedules, I guess Swiss plane should be more common anyway. If they are not, it's a problem of the traffic.bgl, since all parking that have an SAS ALSO have an SWR code, you can easily check this with any AFCAD editor.
and everything was fine with Zürich 1.x ; until I installed Zürich 2.0. I wonder if anybody else with the same setup sees that too.
The airport can't create a flight our of nowhere, it can only indicate a preference were to park for flights that are always created by the Traffic package in the traffic.bgl file. So, if you are seeing only or mostly SAS flights, it can only means they ARE in the Traffic.bgl.
The different that the previous version didn't had any airline code so, they parked randomly based on parking size and you might have not noticed, but the same airplanes were there, since it's not the airport that calls them, it's the traffic schedule for LSZH in the traffic.bgl. With Zurich 2.0 they are more realistically divided into european airlines to Terminal A mostly, and international airlines more to Terminal E.
Note that, the FS9 version already was like that since a while ago, since the FS9 AFCAD was developed during several months following suggestions by many forum users, we simply used the same definitions for the FSX version too.