I suspect they would be slightly impressed that someone was able to find out as much as they did, but I don't think they would be overly surprised. I also suspect they would also be satisfied that this doesn't disclose anything sensitive about the contents of the microcode updates and just found out some information about the mechanism.
They definitely wouldn't be surprised that someone was probing microcode updates. A lot of us have asked them about it and they know people are interested about what's going on inside those blobs.
> I wonder if the handful of Intel engineers who presumably crafted this would ever stumble into this post.
They almost certainly will if they haven't already.