First off I agree that this line of argumentation is a form of gatekeeping. Rust is awesome because it enables a much more diverse group of people to do low level programming. It's about bringing people in, not keeping them out. The undertone of some comments here seem to be classifying certain kinds of people as undesirable to the Rust community. It declares a gate and wants certain people to stay out.
Additionally, seeing how many people in the community seem to believe that a = b can't trigger allocations, or that Rust 1.0 code is guaranteed to still run, I would argue that in-depth awareness doesn't really seem to be a necessity to be part of the community. I wish there was more awareness. My solution is to keep talking about these kinds of things even if there's going to be downvotes. I'd rather be downvoted than keep or kick people out.
And as a final note, we already have enough tribalism. In the Rust community and the software community in general. I don't think it's a good thing to elevate that to some kind of virtue.