Who said there is no radar? How do you think the Operatives interragation ability will be working then if it has no mini map to put the red dots on and display?
While he said there was no radar he clarified the statement by saying "except for the interrogation ability". How do you think that ability would work if there was already an active radar working? Simply put it wouldn't.
Since it seems fairly pointless having a fully working map which only has radar when someone gets interrogated I'd say the radar will temporarily pinpoint the location of enemies when they shoot/make a loud noise. Hence the existence of silencers to counteract that. "Interrogation" will no doubt be similar to COD 4's "UAV" kill streak reward. Come to think of it the map I just outlined is basically COD 4's map. That's not necessarily a bad thing though.