It can be. A lot of other things can cause that as well though.
You have black smoke because the air/fuel mix in the cylinders is too rich and there is not enough air to burn all of the fuel. The PD TDI engine is a relatively dumb engine, so just keeps on chucking fuel in at its normal rate even if the turbo is not performing properly.
A poorly written remap can also cause this. It will overfuel to the point where its actually impossible even with a healthy turbo and induction system, to get enough air into the engine to burn all the fuel. Very bad news for your EGR system.