Welcome to the community!
You should note that it might not have mattered where you purchased your phone. Many android phones (most notably Samsung) undergo a process of SIM-profiling when a SIM is first inserted into the device.
Generally, I did not think that Google phones underwent SIM-profiling as well. However, it's possible those bookmarks were included during the installation of the carrier software environment in a similar process. That same process would have occurred if any of the other Canadian provider SIMs were first used in the phone. In those situations, other bookmarks would have likely been included.
Hope this helps 😀
That's odd that Google would do that on the Pixel phones, I've never had that problem but I don;t have a Pixel 4.
Go to applications and clear the cache and data for chrome and see if it will remove those bookmarks.