Minibox support for MPEG4 conversion?

In in south OC, CA.  I got the letter "Your Cox TV service is about to be updated", and it says to check if channel 1987 is received.  I tried this on my TIVO Bolt and saw a CSPAN show, so I think that is good, but I tried on the Minibox and got the message you see when it isn't receiving the channel: "If you see this screen, please try to change the channel".   I notice the letter specifies CableCards, so maybe the Minibox isn't impacted by the MPEG4 changeover?  I've been happy with the Minibox as a lower cost solution, rather than a full blown cable box.

Does the Minibox work with MPEG4?