I think they are referring to the Pixel 6 [1]. If the same happened again, Google might announce that the Pixel 8 will receive 4 or 5 years of major Android version updates and 7 years of security updates.
However, the alleged leaked specs for the Pixel 8 explicitly state "7 years of OS and security updates" [2], so I think they do actually intend on 7 years of major Android version updates.
Pixel 6 was promising 5 years of security updates from the start. Like, from the very first announcement. As evidence, note that your link is from the time of the launch, not some kind of bait and switch like the OP claimed.
As an owner of an Android phone (Pixel 4a) that just reached EOL and for which a potential 0-click RCE 0day was just released (the webp thing), I'd take three more years of security updates on the spot. But well, I guess time for a new phone.
The link referring to 7 years of update. If you follow the leaker on Twitter kamila in the original leak tweet they mention it can be 5 years of OS update + 3 years of security updates or something along the lines. The leakers isn't sure if it will be full 7 years of OS updates. I think other people reporting on the leak are failing to differentiate OS updates vs security updates making people to think Google rolled back on updates.
Is that still unpatched on the Pixel 6? As far as I can find the CVE has been patched in the Android security bulletin from 2022-11-05, which the Pixels receive (that + the patches specified in the separate Pixel security bulletin).
I don't really understand why you would spend Pixel 4 XL money on a phone that will only receive three years of updates, but it's not like Google hid their support timeline from any of their customers.
However, the alleged leaked specs for the Pixel 8 explicitly state "7 years of OS and security updates" [2], so I think they do actually intend on 7 years of major Android version updates.
[1] https://www.theverge.com/2021/10/19/22735485/google-pixel-6-...
[2] https://www.91mobiles.com/hub/google-pixel-8-pro-specificati...