I read this thread 4 hours ago and was prepared to reply, but had to get to the airport for my ORF-ORD flight. My reply was going to be that I had always experienced the proper boarding order except for a single UX flight with 2 pax (one traveling with me) in which they didn't bother.

Well, at ORF today, boarding a UX (Mesa) flight, the GA announced (mostly verbatim quote with acronyms substituded): "At this time, we'd like all First Class, GS, 1K, Premier Executive, and Seating Zone 1 to board the aircraft."

There was a mad rush, that I ended up at the tail end of (1P with F seat) having to nudge past a boarding zone 4 that was trying to sneak in with the crowd. I don't think they even had a lovely red carpet.