We have removed the workarounds for some of our resolvers throughout the world, and starting on Monday we will continue to remove the workarounds from more resolvers, until we have removed the workarounds for all our resolvers. We will post another update when that is complete.

Name servers that do not support EDNS, but send an error response of almost any kind (NXDOMAIN is not included) are still supported, and Google Public DNS will stop sending them EDNS, if non-EDNS versions of the same queries get successful responses.