bear, upon what data are you basing your idea of overspeed loss => lost radome? At the speeds flown, lost radome likely causes non-trivial drag, likely a radar fault, and hence an ACARS message well before the upset event.
I don't see there being any data presented to date that supports this hypothesis. Indeed, what little we have from CVR is that pilots had noticed something ahead and made a small course change based on that info. So, if radar was not working, that would most likely have come up in conversation.