The problem is not just about interoperability. According to DSA, given Apple is one of the designated companies, they are responsible for security and privacy

The problem is not just about interoperability. According to DSA, given Apple is one of the designated companies, they are responsible for security and privacy while DMA mandates that they allow for interoperability when they add functionalities. It's a fundamental conflict and requires trade off. Apple is likely waiting for the current term to be over in november and then deal with the new regime. Vestager is called a waning star, and she has been most vocal about it in recent times.