This new upgraded silent motherboard is currently not pre-installed on our Ender 3, Ender 3 Pro and Ender 5 printers.
At this point, the silent motherboard is a separate upgrade for all Ender's.
The firmware for Ender 3 /Ender 3 Pro / Ender 5 comes pre-installed NOW
You just plug them in and start printing!
Installation Youtube link: https://www.youtube.com/watch?v=DVRlikq0Hkw&t=54s