Hey @Jkatz (WMF). I was talking briefly with @Moushira about this at all-hands. Wikipedia Library team spent half of last year preparing and running a pilot directing readers to a Research Help portal that explains "how and why wikipedia works, and how you should use it."
We did this by placing links to the portal under the ==References== section of 10,000 articles on English Wikipedia split across the two best organized WikiProjects: Medicine and Military History. The results of the tests indicated that readers and editors with under 100 edits were very supportive of a link to the content. Experienced editors were less pleased. We summarized our findings in a comprehensive report.
In Q3 we are running a banner campaign to get further feedback on the page content; we're also working with a Library School researcher to evaluate the UX of the page. We'd like to explore a way to share this content more systematically with readers, while letting experienced or all logged-in editors ignore/dismiss the content. Part of trust is understanding. Hopefully we can work together on this aspect of the problem. Cheers! -Jake