At the very begining of the program, before they register, couples are invited to meet first with their priest first and check with him.
If he is not familiar with CMP/Catholic Marriage Prep the couple can give him the website’s address, show him what’s covered and so on.
The final decision is always up to their priest!
Many dioceses support the program openly; see list.
Catholic Marriage Prep is also listed by the USCCB (for Your Marriage) as a valuable resource.