Dolby Atmos NCAA football game on Xfinity 4K

Got a real surprise last night when I turned on a football game running through my Sonos Beam Gen2, ERA 100s, and Sub 3! My Sonos S2 app showed the mode it was running was Dolby Atmos! I have just updated Xfinity X1 box to 4K (little round circle with rainbow colors) and did not know what to expect. Sound and picture were definitely better ! I read that upgrading the DTB can facilitate this Xfinity upgrade in different parts of the country. Anybody else get this?