Seems the “next Charlie Hebdo cover” is really this one: TPM Livewire explains what I think was more an honest mistake by many tweeps than any kind of hoax:
In short, blocking self-indulgently, whether out of laziness or anger or boredom or trifling annoyance or whatever obscure motive, amounts to a special kind of trolling: a narcissistic negation of discussion that, like most trolling, would be impossibly embarrassing to a contemptibly contemptuous perpetrator if attempted in “3-d life.”