The Note comes just before the paragraph: "Burning the Bootloader" but after that you find the paragraph "Uploading Using an Arduino Board".
In the latter, they instruct you to remove the Microprocessor from the Arduino board and in both cases 'To program the microcontroller, select "Arduino Duemilanove or Nano w/ ATmega328" '.
So, the exclusion of the Uno appears to refer to both situations.
Thanks for your help.
Luca