After reviewing several Meta posts and related commentary, the moderator team has replaced one of the custom close reasons on the site. The General Reference close reason has been replaced by:
Please include the research you've done, or consider if your question suits our English Language Learners site better. Questions that can be answered using commonly-available references are off-topic.
This new reason more adequately conveys why the community was closing general reference questions (because more research was desired), it provides the same rationale for other questions that might not be considered general reference but are still lacking information, and it also suggests the English Language Learners site, which is helpful for users who may need to learn how to do the research in the first place.