Well, others had discussed whether he'd get fired, but I think the consensus was that he wouldn't because it'd be a bad PR move.

However, I don't think it's correct to say that they would have been firing him "over a rant". They would have been firing him over a lengthy, detailed, public (intentional or not) criticism of the company that went after the most senior company executives by name.

I don't think he should have been fired, but I think something like that would be considered at least a "fire-able" offense at pretty much any company.