TL;DR the link is about Ukrainians vs. Poles, not about Jews and/or Holocaust

Ukrainians and Poles were enthusiastically massacring each other for hundreds of years for various reasons (Catholics vs. Orthodox, serfs vs. land owners, nationalists vs. nationalists and so on). This part of history is accepted by both sides. It's true, that collateral damage included Jews sometimes. Some Eastern European Jewish historians describe it as "always choosing the wrong side". Jews were targeted for managing estates of Polish nobility, participation in establishment of Communist rule in Ukraine in 1920s, participation in establishment of Soviet rule in 1939-1941 in Western Ukraine. But they were never targeted for being Jews.