In my experience no one likes seeing single-letter variable names (except for i, but I have even heard criticism of using e to represent an error). As for your second example, whether it provides clarity or convenience is entirely situational. If you have a long render method then specifying that a variable is coming from props may be helpful but the most common standards call for props to be passed to a functional component that has a single responsibility, i.e. destructuring props and rendering its respective values.

Sorry if I missed something but I also don't see an endorsement of bad variable names in the OP's handbook. The comment just seems a little out of place, thought I mostly agree with it.