I looked to see the code review requests you’d put up, but I couldn’t find them! Since you, apparently, care more than me I’m happy that you’ve put time into improving the system.
No, he’s proven that some transit providers are (sometimes) dropping NTP queries. One of them is a global carrier mostly focused in Europe. We’ve talked to them and they believe the risk of being affected by ongoing NTP based DDOS attacks is too great to disable the filters.