Yeah Belicheck is never in any NFL licensed games. This was taken from the wiki page on him
"In the
Madden NFL video game series his name is not used and is known as "NE Coach" because he is not a member of the NFL Head Coaches Association, which licenses the game. Belichick is the only NFL head coach who has chosen not to join the association."
I think the Josh/Donny guess is correct too, I vaguely remember some post earlier this year where they mentioned something funny being in place of Belicheck this year.