Every Intel microprocessor out since around 2002 has allowed firmware updates thru updating the BIOS.
There are also wired fuse settings on-die which allow processor features to be enabled-disabled during testing time.
The goal is to optimize the number of die thru the system and allow different products to be created off a single generic die.
It is not used on all product lines but many of them
Is that to say the Intel CPU incorporates programmable characteristics — something like an Altera or Xylinx FPGA?