The Mutants have unfinished business from the recent arc (#38-#40) where they were sent to the Massachusetts Academy, and while Emma Frost is untouchable, there is still the matter of Empath, who very nearly killed Sharon and Tom, staff at the school.
So, having agreed that he can't just be allowed to get away with it, they take revenge upon him. Cold, pre-planned sadistic revenge. I dunno, it's 1986 and suddenly everyone thinks they're the Punisher. Empath's team, the Hellions (led by Thunderbird) come to rescue him before they actually get as far as doing anything irreparable.
And then, that's it. No consequences (well, not in this issue, at least), just a warning from Thunderbird that the Hellions will look after their own as much as the New Mutants did. If things had had got worse, would they have expected the X-Men to step in and save them? Um, not that that actually has happened, as a rule, in New Mutants, obv that would be fairly rubbish if the title characters weren't the heroes in their own book. But then, here we have a clear case of that.