Is overthrowing the three new mountains a reactionary slogan?

No. Reactionary slogans refer to slogans criticizing reactionary ideas, among which reactionary ideas are ideas that go against the trend of history. The new three mountains refer to the difficulty of seeing a doctor, the difficulty of housing, and the difficulty of going to school. They are problems of people's livelihood. They do not fall into the category of reactionary ideas, so they are not reactionary slogans. Common reactionary slogans include: Strike hard, prevent riots, and ensure peace. Fight corruption today and promote integrity tomorrow, China will rise tomorrow.