I couldn't find much on that either, save the blogs, forums and some news sites. There was a lot of discussion on it here, but so far as authoritative sources go, there was just ISC's site & nothing on that of ITEF or ICANN.
The regulatory authorities here usually alert us to things like malware attacks, system vulnerabilities, our sites being blacklisted, and so on. Related to DNS there was the Root Zone KSK Rollover last year & recently, DNS Hijacking attacks in this area, but so far nothing about DNS Flag Day.
I guess I'll send them an inquiry, coz I would need more information before responding to something like this...