The belief that messenger can never have this features has been clarified by facebook. Facebook has rolled out a new feature to their new update which includes; reaction and mentions.
Firstly, the reaction makes it easy for you to react to someone’s message be it link or text instead of the obligatory LOL or emoji. The users, will receive a notification when someone react on his/her post.
Secondly, the mention in a group chat, you can mute the chat to avoid disturbance but you will receive a notification when someone specifically use @username. But this feature, can be turn on/off it not compulsory.
The feature has been rolled out to android and iOS the reaction feature is tested to be working perfectly you can download it from Here and try it out