I wonder if they fixed the iMessage caching-phone-numbers-after-you-switch-to-Android bug that's been so terrible? Really wish they had a FULL changelog, not just marketing spin.
Just to be clear, this is when one of your contacts who formerly had an iPhone but switched (to an android in your case), it still tries to send via iMessage and silently fails? Yeah, that one sucks, I sent a message to my brother in law congratulating him on his engagement and he never got it. I found out awhile later he'd changed away from iPhone :-/ Annoying. And then trying to change my phone to actually send him SMS instead ... I'm still not sure it's working right.
I think that is not driven by the OS but instead Apple's backend services. I'm not sure if the iMessage service knows when a number is no longer bound to the iPhone.