Problem: We make a ton of assumptions about what new editors need to see on a talk page in order to participate in an informed way. Instead of barraging new users with templates atop the talk page, if a WMF team performed user testing on (1) what editors (new and old) found useful about talk page banners, and (2) what they actually learned from reading them, the community would have a clearer understanding of what information to cover and what to excise.
Proposed solution: Perform usability testing on the talk page banners of several Wikipedias and share findings with the community; bonus: recommend a design with information hierarchy for the community to consider and potentially implement
Who would benefit: All talk page readers and editors, especially new ones
More comments: To my understanding, this is a blindspot of the editing community, as we do not have the communal resources to perform user testing without a centralized team like the WMF's. Many community UI elements could use usability testing but the talk page banners is one of the most glaring opportunities.