This feature is on the backlog. I will update you when we have more details to share.
Adding any emoji as a reaction remains under review.
I am marking this as partially done to let you know a new reactions bar with Like, Heart, Laugh, Surprised, Sad, and Angry has begun rolling out to all users.
We’re updating our command library all the time, so keep checking the menu in the command box to see what’s new by typing / or @.