Wolfram is definitely not a crank. Cranks do not understand scientific methods and also have a minimal understanding of whatever field they're trying to be active in. Like trying to push physics theories while demonstrably failing to understand high school level calculus. Cranks are also conspiracy theorists who inevitably believe knowledge like theirs is being suppressed.

Wolfram does display a similar ego to cranks. He tends to place his cellular automata at the same tier of importance as general relativity or wave-particle duality. But unlike cranks, he doesn't say that Einstein, Feynman and other greats are wrong, he doesn't "prove" his theories by math-looking babble that is definitely not math. He loves cellular automata and so much of what he writes is more like philosophy of science than science. He will model certain processes as an automaton and then he jumps from that to every natural process being a cellular automaton.

Eccentric, definitely, and most of his physics research isn't accepted but he's several orders above the level of crank.