Kudos to the OP for this post. I have often noticed it- on US airlines only- and find it quite an annoying affectation. I'm quite sure it's not part of the script-
It's like people (police officers and sports team coaches are notorious abusers) using the word "individual" rather than just saying "person" or "man" or "woman." I think they think it makes them sound more intelligent or articulate, when the opposite is the case.
hurlimann