Users' behavior had nothing to do with the cancellation. The decision, as always with corporations, was based entirely on economics. Yahoo has decided that it does not want to bear the cost of maintaining the servers necessary to support answers.yahoo.com.
No, many trolls spread misinformation and lies. That's quite different from just stating an opinion. Social media sites are being held responsible for the active, malicious spreading of lies about things like COVID and the vaccines. BTW, it seems to be conservatives who are trying to "cancel" everything now. They've called for a boycott of companies like Coca-cola for expressing an opinion about the Georgia anti-voting laws.