They're not being dishonest in characterizing this as more than a simple acqui-hire; most of the functionality of Sunrise is faithfully replicated in Outlook for iOS now (which, if you're not aware, was actually itself born out of the acquisition of a multi-protocol email app called Accompli, and still includes support for a variety of non-Exchange mail services). Unfortunately, missing features include the long-press natural language "quick-add" input box, and setting multiple reminders on events.