No.
Interoperability is only required, if you have a significant market share. Apple does not have this in the EU. iMessage specifically doesn’t fall under this regulation, since hardly anyone uses it.
And since Apple plans to publish an SDK for their intelligence anyway, you can’t really regulate them for being too closed.
So either that’s a purely political retaliation, or their “super privacy friendly” services aren’t as privacy friendly as they claim.
Apple does have a significant market share of 25-30% in Europe. Just because they avoided having to open iMessage (for now) because everyone in Europe uses WhatsApp, doesn’t mean other Apple services are safe from regulation.
But I’m with you - it’s more likely about (not so) privacy.