7 years of updates for what? The S24 models and up? Or all phones up to 7 years ago? It doesn't specify, and the cynic in me makes me think it's only on 2024 models as a selling point.
https://support.google.com/pixelphone/answer/4457705?hl=en
GrapheneOS end-of-support info (for Google Pixels):
Short windows made sense simply because it was a lot of work to maintain old devices. Now that there's a more solid separation of concerns, longer support windows make sense.