Has anyone had an interview waived but then been asked for one later, and now you’re wondering which update is the real one?

Yeah that can totally happen, the system sometimes throws out that “interview waived” update before an officer has actually finished reviewing everything, and later on they might decide they still want to see you in person, so the second update is usually the one that matters and it’s not a bad sign, just USCIS being a little messy with how they post things.