I'm not familiar enough with the law of statelessness to offer a reasoned opinion, other than to maybe offer a personal one.
As I said, my late father came here and he was stateless. We're talking about the late 1940s. At that time, he ended up working towards Canadian citizenship. I don't know if that has changed today. I am uncertain.
It would seem to me that the professor is quite correct, that there has to be an obligation. I would imagine that Canada accepts that obligation. If it needs to be codified, then it should be codified, because no one should be stateless.