Disgruntled Hobbit
Adventurer
RightBesides Tales from the Yawning Portal and Ghosts of Saltmarsh? Probably the SCAG. Before that, the PHB, DMG, and Monster Manual, which took a huge design shift from what 4e was like to be more like 3e. (I think Van Richten's Guide to Ravenloft should qualify, too, as it was designed with both newer and older players in mind, but you've already made up your mind on that.)
GHOSTS OF SALTMARSH from 2019. Early 2019
With work started on that in 2018, if not late 2017
Before they started being aware of how many new gamers were coming into the game
Instead of doing another reprint this year they did an anthology of new adventures by new writers
GHOSTS might be the last reprint and the last book where newcomers aren't they key audience