I read this article earlier this morning and I have one question that I haven't found the answer for: Are the old Intel firmware blobs still available somewhere, and can we choose to not load this "upgrade"? If yes, how do we revert?

Unless your firmware vendor updates the microcode embedded in your firmware and you update to that newer firmware, the new microcode is loaded at runtime and won't persist over power cycles. The old microcode is still available, yes.

Yes, I understand that the upgraded firmware is loaded after boot (unless burned into the MB ROM). What I'm looking for is availability of the old firmware blobs. Intel probably has copyright on them and can control their distribution.