As someone who’s personally worked on dozens of M&A driven vertical integrations and “ecosystems” (lol)…interoperability is inherent to being a first party.
3rd parties aren’t going to get the same access or treatment for a number of reasons…many of which Apple has outlined.
There are several reasons for a platform to not want to offer 3p interop, from security to privacy to competition, but the DMA is targeted EU regulation to mandate interop specifically for the big tech cos’ platforms and this is one of the first major tests of the law.
3rd parties aren’t going to get the same access or treatment for a number of reasons…many of which Apple has outlined.