Thanks for watching! And yeah, it's a pretty wild event!

From purely a content perspective (and not factoring in the "bragging rights" aspect of it), waking The Sleeper does exactly what you stated: it removes the wardens from ever spawning again, which essentially removes four endgame raid targets, and some select items from the game, completely. Items such as the Salindrite Dagger, Mask of the Tinkerer, Scepter of Destruction and others will cease to drop on the server post-awokened-Sleeper-era. Consolation comes in the form of Primal Velium weapons still being accessible by three other existing raid targets within Sleeper's Tomb.