And in many cases the comment would not have been made without the click on the dislike button.I am not sure I follow you here, please explain.
Concerning the "harassment potential": I've got the opinion that you cannot solve social problems with technology.It's true but technology can still enable or damper negative behaviors. Twitter's all-public centralized model definitely enabled mass pile-on, while Mastodon's choice to not support quote-boost makes it slightly harder to add a snide remark to a boosted toot. Sometimes it's all it takes to prevent a toxic behavior from scaling/spreading.
I‘m not against emoji reactions even though I probably wouldn’t use them myself, but I’m against the idea of replacement. The Dislike removal shouldn’t be tied with the emoji reaction addition.