How could this situation have been de-escalated? What could the different people involved have done?

Felicia and Jen are friends from school. They both audition for the lead role in the school play. The next day, the drama teacher, Mr. Adler, posts the final cast list, showing that Felicia was selected for the role. Felicia posts a photo of the list on social media with the caption "Guess who made LEAD ROLE!! ME!" Other students at her school see the post and make comments.
The comments continue to come in. People start responding with #teamjen and #teamfelicia hashtags. Later, in response to Jayden's comments, Felicia posts an embarrassing picture of Jayden and calls him out for failing Mr. Adler's class.