I guess that, if one interprets "cloud" as meaning "the involvement of anyone else's computer at all", then to do the lookup on the domain, the user is going to have to go to the .tld root server, even if one runs one's own authoritative DNS...
But that's not perhaps the most common interpretation of "cloud"!
(I've yet to move authoritative DNS in-house, but it is on my list.)
The aforementioned machine 20cm from my left elbow has a content DNS server, too. Not wholly satisfactory as it's not a guaranteed stable address.
It's doing double duty though, with split horizon, as the root content DNS server for the LAN, serving copies of the ICANN data and the data for Estonia and the island of Niue.
You'll know that you've truly arrived in the self-hosting world when you have your own replica of Niue. (-: