I'm pretty sure they meant Racket-specific queries that have enough context to make clear it's the language, not just plugging the term "racket" into the search

I'm pretty sure they meant Racket-specific queries that have enough context to make clear it's the language, not just plugging the term "racket" into the search engine. The point being that Google is better at picking up the context of queries, even when they don't have your search history.