What does 「予定調和」 mean? Not that stuff about Leibniz, but in daily chatter.
I think very few Japanese people recognize that 予定調和 is from Leibniz (I didn't know that). When this appears in daily conversations, it means "safe but expected result", "without surprise/trouble", "never changing", "repeated many times", "according to the scenario", etc.
Typically this is used for long-running TV series like サザエさん, where characters never get old for decades.
It may have some negative nuance. If you see 「国際会議は予定調和で終わった」 in a newspaper, it probably implies the meeting was boring and unimportant.