its a slur and they didn't take it as a joke; The captain of the team also made it abundantly clear that he didn't recognise their legitimacy - "they are a male team pretending to be a transgender team". Funny fucking joke

using transphobic slurs, isn’t about shaming people for their political beliefs; it’s about addressing actions that hurt others. Respect for all individuals, regardless of their gender identity, is a basic human right, not a political stance. What you describe as 'plain facts' might seem that way to you, but using slurs against any group crosses the line into disrespect and discrimination, which is a behavior that deserves to be called out