Facebook will organize the reaction system differently. Because of the many responses among messages, too much noise is often generated and that is why the social medium wants to put important responses at the top. The company reports this in a blog.
Pages and profiles of people with many followers are the first to receive the new response system. Preference is given to reactions with a lot of interaction, such as likes or new reactions.
Responses from those who posted the message have the most value. In this way, Facebook wants to ensure that users always see the most relevant responses and reduce noise.
The feature is enabled by default on pages and profiles with many followers, but anyone can enable this for their messages in the profile settings.