Counterexamples that come to mind are Neuromancer (AI driving the plot) and Blade Runner (AI antagonists.)
A compromise thesis might be that in cyberpunk media, AI is at never powerful or motivated to fundamentally reform the worldwide crapsack economic system. They don't abolish corporations, although they might take them over.
Of course, if there was a story about an AI taking over the world into a post-scarcity society, it probably wouldn't be filed under "cyberpunk" either...
Rampant capitalism is kinda genre-defining for Cyberpunk so Cyberpunk without corporations wouldn't really be Cyberpunk. _The Matrix_ only qualifies as Cyberpunk because within the matrix the machines effectively control the capitalist power structures to exert their influence.
Abundance/scarcity isn't really about availability, it's more about access. You can have a cyberpunk story in a "post-scarcity" setting in the sense of availability (due to sci-fi tech) but you can't have it without unequal access to those resources.