Doesn't seem so, just checked Chur -> Zürich HB, for Sunday "SBB Mobile" offers a ICE starting from Chur at 12:35. Basel SBB -> Zürich also offers ICE connections.
AFAIK there are less ICE trains running in Switzerland due to the issues, but the remaing ones still seem to appear in the trip planner.
You're right, it seems like this is exclusive to the EuroCity between Munich and Zürich which is a cooperation of DB, SBB, and ÖBB.
I happen to take this train on a regular basis, and it is reliably delayed :-).
Conveniently, my connecting train is also usually sufficiently delayed so that I do not miss it.