THERE WAS ONLY ONE FONT ON TELETYPE MACHINES AND NO SHIFT KEY.
otherwise, the teletype format would have been all lower case.
I've no idea, though, why the NWS retains the old teletype style for their announcements, now that they're being delivered via the Internet.
A lot of the old timers are still around would be my guess.
I recognize many of the forecasters names from when I was in radio in the early and mid-80s and those alerts came across the old AP wire teletype machines.