I'd not heard that
The opinion I quoted comes from the years when Polish immigrants started settling in GB.
theguardian.com/society/2007/apr/15/asylum.raceintheuk
claims of racist behaviour among Polish children and their parents. Headteachers reported that pupils were moving their desks away from Asian and black children in fear and saying that white people were superior.
In one case Polish children drew pictures of apes sitting in palm trees and claimed this was what their black classmates looked like, while in a school in Acton, west London, a group of teenagers hurled daily abuse at non-white staff and pupils.
A lot has changed due to contacts of Poles with the world but this racism is still there, hidden in souls and minds. Racists are especially males, women are more broad-minded.