> One of the things the whistleblower mentioned in her 60 Minutes interview is that European political parties complained that Facebook incentivizes taking more extremism political positions.

Not much love for Facebook from me, but literally all of the European political parties complaining are just looking for a cheap scapegoat for their own failures. Strings of corruption and lobbyism scandals (especially in the conservative and long-establishment parties), other personal utter failures to lead a party or country as well as failure to see and act upon the side effects of three decades of rabid globalization and unregulated hyper-capitalism past the fall of the Soviet Union are what led to the erosion of the classic European Social Democrat and Christian Democrat-type parties.