To be clear about this issue, it only affects computers with an Assus motherboard, and UEFI, and Secure Boot. And Asus has issued a workaround/fix. Actually the fix should have come out when Asus first learned about the problem with this Update when it appeared, so they do share a bit of the guilt. But Microsoft's upgrading from "Optional" to "Recommended" is pretty weird.
Sure provides some fodder for the conspiracy theory gristmills. :)