I don't know, I have a Pixel 7 and only bought the Watch 2. The promo may only be available if the Pixel 8 is bought directly from Google. In any case, I can recommend the Watch 2. When setting it up, it is essential to set up a Wi-Fi connection first. It always breaks off via Bluetooth.

From tomorrow you can register your purchase on the Google Store page somewhere. Unfortunately I don't have the link right now.