This has nothing to do with root zones. The root zones tell a resolver where to send the next query to find .org domains, for example. They don’t know about your zone, nor should they.
> pdns196.ultradns.org as an authoritative NS for my zones
Okay, sounds like what most registrars can do. (Although Cloudflare seems to have very odd concepts of what DNS means…)
> but if I rack mount a server and expose DNS using one of my domains
I can’t parse this. Are you saying you have a server with a fixed IP address and it’s running an authoritative DNS server for one of your domains?
> people will only learn about it when they query my NS records from other DNS servers that are already defined such as ultradns, google, etc...
This almost sounds like common recursive resolvers like 8.8.8.8 can find you, which is what you would expect.
> because they already queried NS from pdns196
Queried NS for what domain?
> meaning to your point that one I just provisioned will lack glue records in the root DNS servers.
Of course it lacks glue records in the root servers. It’s the servers for the level in which you are registered that should have the records.
Maybe post the output from dig +trace [domain] and explain how the output differs from what you expect?