I wouldn't say "never". DMA is inherently political at its heart and designed to target US big techs precisely. Apple is not immune and EU gave the regulation board enough flexibility to target all of US big techs. Apple knows this and they decided to support RCS for this exact reason to gain public supports.
> The other one, which is more important in this discussion, is that the EU kept the definitions of services rather broad to the degree that Apple’s adoption of RCS will automatically fulfill the interoperability requirement.
EU already has defined iMessage as a separate core platform service from iOS and Apple hasn't argued against it because it would give them a chance to exclude iMessage from the scope of the regulation. Hence, OS level support for RCS won't cover iMessage if it's also designated as a gatekeeper.
The first one is that, despite the EU’s blatant attempt to carve the rules around the likes of Apple while simultaneously trying to shield EU companies, they've overestimated the amount of iMessage users, excluding iMessage from the DMA rules.
The other one, which is more important in this discussion, is that the EU kept the definitions of services rather broad to the degree that Apple’s adoption of RCS will automatically fulfill the interoperability requirement.