As Ace correctly deduced, it was for the new management to preserve the illusion that CNN is still a legit news organization and not the whorehouse propaganda machine it really is. Zucker’s “firing” for hanky-panky and not because of being a media arm of the Cuomo and Democrat machine, is supposed to preserve that in the eye of the public. Or so they hope.
New York Magazine: Jeff Zucker’s Relationship with Allison Gollust “One of the Biggest Open Secrets in Media”

CNN’s media reporter [and bipedal thumb/tuber] Brian Stelter confirmed Wednesday afternoon the company would use “three longtime members of the CNN leadership team, Michael Bass, Amy Entelis and Ken Jautz” as the “interim co-heads for CNN beginning today.”
CNN Names Three Temporary Replacements For Jeff Zucker

“Disgraced president Jeff Zucker’s resignation yet another humiliation for low-rated entertainment channel.”
REMINDER: CNN Is a Clown Network Run By Creeps

“Jeff Zucker, a world-class sleazebag who has headed ratings and real-news-challenged CNN for far too long, has been terminated for numerous reasons, but predominantly because CNN has lost its way with viewers and everybody else.”
Trump’s Response to CNN’s Zucker’s Resignation Is Everything You’d Expect It to Be