Whether or not you're the only person who does this is irrelevant. It doesn't prove or even add any weight to your baseless speculation that the switch is pre-meditated. You're just making stuff up, plain and simple.
+1
Airlines have better things to do than to engage in such bait and switch. Average Joe Blow, and thus 99%+ of passengers, can't even tell a difference between an A330 and 777 and couldn't care less about the specific aircraft.
And airline ops have much more important things to do, such as keep planes in the sky and flying on time.
This happens all the time with all airlines. Anyone who's flown more than a few flights will know that from first hand experience.