their pledge is "Pixel 6 and later Pixel phones will get [updates] for at least 5 years from when the device first became available on the Google Store in the US." where [update] is security and may include features, (and I guess even feature removals) etc.
I have a Pixel 3, which received less than 2.5 years of secure use between time of purchase and time of last security update. I'm looking for a new phone that isn't made by Google, preferably one that has an open platform, because I don't trust Google as far as I could throw their advertising department.