After a bit of research, I’m forced by facts (NS records can be cached for an undetermined time) to see what you’re saying. Thank you for teaching me.
The workings are, of course, a bit more complicated than what either of us have said (here’s a taste), but there is a situation as you describe, where separating the registrar from the name servers, and the name servers from the domain, could save the domain from going down.
And, as a quick aside, a side effect of the sweetener is to damage DNA.