There's absolutely nothing to suggest that. Pixels have been a successful phone lineup and Google extending the minimum support period for Pixel 8 and later and expanding form factors by making tablets and foldables should suggest the opposite - guaranteeing they'll support those phones for 7 years is a big statement to make.

We have always said we'd like to see other OEMs meet our security requirements or work with us to make a device for GrapheneOS, but, we have no concerns on Pixels.