These examples illustrate using escaping in label matcher label value regexes, but this is the section about PromQL string literals. The "strings" in label matchers are not a string literal in the PromQL sense, but just a syntactic part of a vector selector node (not their own expression). So I would either move this to wherever label matchers are explained, or use a different example here where you have to escape something in a PromQL string literal - probably only in the case of thelabel_replace() function regex.

Makes sense, will move to matchers. Perhaps leave this too, but converted to label replace example, thanks!