Did they really change a meaningful word like that after publication without an edit note…?

This has definitely happened before with e.g. the o1 release. I will sometimes use the Wayback Machine to verify changes that have been made.

Wow sounds pretty shady then.

Eh, I'm no shill but their marketing copy isn't exactly the New York Times. They're given some license to respond to critical feedback in a manner that makes the statements more accurate without the same expectations of being objective journalism of record.

Yes, but they should clearly mark updates. That would be professional.