Hello, all!
The Age of Empires IV Public Update Preview build has just been updated to more closely align with what will be officially released in the Spring update. To coincide with this update, the Age IV PUP has been extended through the weekend to Monday, March 28th at 10am PT (17:00 UTC).
Head over to the official PUP forums on Steam to view the release notes (note that you must own the game on Steam and be logged in to view).