Has something changed then? I ask because this 2008 MPEG-4 announcement from HBO ends with the following:
Verizon remuxes the Mpeg-4 stream back to Mpeg-2 to use in their system.
The HBO/Cinamax stream is MPEG-4
"HBO/MAX MPEG-2 digital feeds will continue to be available:
The MPEG-4 HD feeds are incremental to HBO’s MPEG-2 offering. HBO currently plans to continue to provide the MPEG-2 HD feeds of HBO (East and West) and Cinemax (East and West), and we also plan to continue to provide all 26 SD feeds in MPEG-2."
It makes sense to me that HBO (and most programming providers) would continue to provide MPEG-2 for all the cable systems that are still MPEG-2.