In 1968, there were still 40,000 Jews in Poland, but there was an “anti-Zionist” purge implemented by Gomulka, that forced most of the remaining Jews to leave Poland.
This was an action by Kruschev to eliminate all members of Stalin, so "why not blame the J**s for Stalin" -- the standard commie way of finding a scapegoat.
But ordinary Poles did see through this ruse (Poles tend to be cynical about authority!)