4...Bb4 or 4...Nf6 are both good for Black. Non-symmetrical placement of the pieces can lead to Black getting a good game in the Exchange French.
For example if 4. Bd3 Bd6 5. Nf3 Ne7! Perhaps if White castles kingside, it could be advantageous for Black to castle queenside.
I (you) know that it's statistically a drawish position, but at least a game has to carry on, right!?. Since it's white turn to continue, presumably white responds with 4.Nc3 attacking black d5 pawn, what would be the continuation for black?
*PS : Internet mostly doesn't discuss the exchange variation, I assume because it's going to be a boring game for both sides (draw).