The complaint is against Google, not any particular domain registrar, to be fair. At first glance it seems like you’ve botched this roll out for the (preventable) reasons mentioned above. Wordpress, although I didn’t agree with some choices they made when doing it, did a wonderful job rolling out the dot blog TLD, as a counterpoint.
We literally cannot coordinate anything between the registry and registrar though. I agree with you that we (the registry) could have done a better job on our marketing website in making it clearer which registrars offer support for which phases, but beyond that? Not sure.