No, it's not something that's refutable. It usually transposes to the Ragozin after Nf3 and Nf6. You do have the option of playing 4.a3 to see what black does, he can either take, going in to the Nimzo-Indian after Nf6, or he can retreat to e7 and you can transpose back to your exchange variation. Either way it's all perfectly playable for both sides.
What to play against this QGD line?
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it's not a main line but probably only because it's slightly more committal about the d-pawn than other lines in the nimzo. white can still take on d5 and try to prove that bb4 sticks out as misplaced in this structure but that's not much. perhaps one upside is it stops bg5 lines and so if white wants to insist on bg5 he has to pay nf3 which is a commitment in itself.
While i was studying the QGD exchange variation i looked up if there was any ways black could avoid the exchange variation. I found a few but this one interested me the most becouse i didn´t find a way to refute it, and the fact that the variation had over 2k games made me wonder why there are no videos on the topic.
So what do people play against this opening? and is there a way to easily refute it?