For Madden 18;
They don't say the first name. And If you drafted Clay Rodgers, they'd say his last name in game BUT if you were to edit his name at all or change another player's name to Clay Rodgers, they wouldn't and just say the generic "QB back to pass".
This is why I'm concerned about it being in the game, editing removed the last names being said.
They should have full first and last name database that can be edited and mixed all day long and announcers should say both first and last in the game.