Sadly, I suspect (while not having read the DMA myself) that what it would require is some kind of published format for interoperability...meaning that Facebook would publish the FacebookStream API and Instagram would publish the InstaStream API, neither of which would actually look like any existing formats (or each other).
Would this work to get the EU to say they've fulfilled the DMA's terms? No idea. But Facebook has yachtloads of cash to throw at legal battles, especially where it sees a potential existential threat.
Would this work to get the EU to say they've fulfilled the DMA's terms? No idea. But Facebook has yachtloads of cash to throw at legal battles, especially where it sees a potential existential threat.