While Apple has not yet publicly responded to the latest proceedings, the company has previously stated that it is committed to working with the EU to comply with the DMA. The European Commission has

Fail to comply may cost up to 10% of annual revenue The European Commission intends to force Apple to open its walled garden.… On Thursday, the EU's executive arm said it initiated "two specification proceedings to assist Apple in complying with its interoperability obligations under the Digital Markets Act (DMA).

The need to ensure Apple’s business is viable might turn out to be a very big deal. Europe has already fined Apple billions to protect the interests of European firm Spotify. It has clawed back (as Apple sees it) $14 billion in tax money. And yet, at least according to John Gruber, the EU contributes perhaps 7% of Apple’s global revenue.