The combination of a lack of an official response from Apple yet, the fact that this was apparently found by beta users (not that the issue is related to 9.3 directly, but it was reported as a beta issue by some), and the inability to change default browser leaving my phone in a pretty broken state has got me seriously considering a switch to Android though, where at least such a bug could probably be worked around through changing defaults or worst case flashing a new ROM.
The iOS 9.3 release suggests Apple's QA process is rather lacking and incidents like this won't help confidence in their devices - it's okay for users who know how to work around it and understand what is going on, but my parents would probably think the whole internet was broken!
Rant over, glad to see this on HN as it has been p*ing me off for a few days :)