Agree with the observation on limited letterbox format with SD DirecTV / UTV. However, I have a 4:3 projection television and set the UTV to the same 4:3, so I guess I am relying on the upstream feed for the 16:9 signal. No weirdness with stretching of the picture.
On a side note, TCM broadcasts almost everything in letterbox, uncut and without commercials. I see Spike, BBC-America and AMC still showing letterbox movies as well, however they suffer from commercials. I use the advance search feature and select letterbox when searching for content. I bet 2/3 of the returns are TMC.