No. Apple somehow convinced people that: "our products work great with each other" *must* somehow involve: "we won't let competing brands work well with our products". Slick marketing!

The EU's warning involves the iPhone's interoperability with other watches and headphones when it comes to "notifications, device pairing and connectivity" (quoting Euronews). For example, you can reply to texts from an Apple Watch, not a Garmin (it works fine on Android). That's an arbitrary software restriction.