Depends on what you qualify as a "masterclass" surely?
If I wanted to know how to play a particular bass line, or study a particular technique, I'd save myself a shed load of money and go onto youtube and take my time watching the variety of technically proficient musicians demonstrating said techniques/tunes.
I might even invest a bit of money in lessons, 1:1 with a tutor and learn/study a technique, etc.
I'd want something different from a "masterclass" at a trade show.
It's an opportunity to ask said musician questions on different things like, how they achieve a particular tone, what studio equipment did they use on a particular track, what is the musical relationship like with the drummer for instance. Or how did they write a particular bass part and many more similar non technique questions.
Personally I'm not a fan of N.O. or that genre, but I think there's enough Hooky fans to warrant him giving a Masterclass.
Stop with the "only the pyrotechnically gifted are worthy" none sense, please!