I can’t 100% confirm Madden 21 but they got rid of the unique cpu generated names being called years ago. Currently, as of Madden 20, there is a specific set of last names that can be used and an offensive CPU generated player will have their name called.
Defensive players whether you change the last name or not will never be called, same with kickers and punters. And first names don’t matter.
I have a RB in Madden 20 named Jack Tomlinson and sometimes they reference LT2. Other players I’ve had on offense named Bishop and Dawkins will get their names called.