Was looking over the articles concerning this whole project and have to say Liefeld's leaving is very strange. There's nothing in any of the announcements about this series that really give any indication of what it's about - other than it's apparently a bunch of inter-related one-shots? So what the big deal about the spoiler is, is baffling. Even with Liefeld posting the pic himself and complaining about it, there's no real indication of what the deal is. Maybe something suggestive of a major plot point, but without context it's just a pic that could be interpreted in a variety of ways.
I wonder if he really left because of this or for another reason. Because SJNeal is correct: to assume there won't be advanced spoilers in 2021 is simply silly.