Well the 319 was at the time. NWA's 319's were still being delivered. I don't see anything cocky about the copied Northwest statement. In fact you embellished it.

As for Delta on SEA-BOS, this is what Delta does. Even though someone notes the PDF schedule shows the 73H every day, we all know the standard-issue 738 gets swapped frequently. So there will certainly be times someone boards in BOS for a 5 hour flight with nothing but overhead video.

And there will be times that even the Delta App shows personal TV 45 minutes before departure and you can tell it's a standard issue 738. Long a complaint of mine.

That said, there are now times that 738's are still showing standard-issue overheard entertainment and they've been overhauled with live TV and such.

73H : 737-800 (W) with personal TVs
738 : 737-800 (W) overhead