Hashtivism: the hashtag revolution?

It was a year ago. In the wake of accusations of sexual harassment against American producer Harvey Weinstein, #metoo and #balancetonporc were born. Hashtags to bear witness, to denounce, to mobilize. A kind of dʹactivism on social networks, dubbed "hashtivism", that we had already seen with #bringbackourgirls or #jesuischarlie. Is this a new form of online activism?