That's not so. The dismantling of the CCP was a precondition of the Concordat. It was part of the deal. Here is what Time Magazine said about the deal back in 1933 when it happened:
"Before the initialing took place German Catholics were forced to bow the political knee to Adolf Hitler, hoping all the while that the concordat would safeguard their religious rights. As a peace offering to the Nazis, they dissolved their Catholic Centre Party, the Party which fought Prince Bismarck so stoutly three generations ago." [Time magazine link at post #188]
Had the CCP not been dismantled, there would have been no Concordat of 1933. The deputies dismantled the party as a prerequisite for the Concordat.
Time, anticlerical as always, hoped it was true.