Keaqueattoish26
The airport station is not and has never been completely closed. There’s actually some construction/maintenance work ongoing since several months, and only one of the 4 tracks could actually be closed at times.
Nevertheless, this very morning, my train (IC5 St. Gallen - Zurich) stopped at the ZRH airport station as usual. And if your train was somehow affected by a track closure, that would be reflected in the online timetable.