https://github.com/intel/intel-linux-processor-microcode-dat...

  $ echo 1 > /sys/devices/system/cpu/microcode/reload

At boot time, the following package provides the latest Intel CPU microcode data files on NetBSD.

  sysutils/intel-microcode-netbsd

  cpu 0: ucode 0xf0->0xf6
  cpu 1: ucode 0xf0->0xf6

Yes? It is regularly; both the firmware or the OS can deliver updates depending on configuration. The Raptor Lake CPUs in question have gone through an enormous number of microcode revisions already due to quite famous voltage scaling issues; it's unclear if this errata is fallout from or related to a similar root cause or just another issue with the processor.

Why is this downvoted? (At the time of writing, the text is grey, so it has at least a few downvotes.)

This is a good question. As others have noted below, yes, and sometimes you can see kernel logging on start-up when the microcode is loaded.