Reactions allow you to add emojis to Posts and Post Comments. Reactions are enabled by default, but Admins or Team Leads can disable this feature if necessary, based on the requirements of the Team.
To disable reactions:
Go to the Manage Teams page.
Click or tap on the ellipsis icon next to the team where you want to disable reactions; Select Edit Team Settings
Uncheck the box next to "Allow reactions on posts and comments":
Be sure to select "Save Changes" before navigating from the Edit Team dialog box.
Unchecking the box will disable reactions on both the post and in the comments section of the post for all posts in that team. If you want to turn off this functionality for every team, then you will need to uncheck the box for each Team individually.