"Are you thinking the outcome would have been much different if she threatened to kill Mexicans on Teams at work instead?"

Yeah, she'd probably get fired but law enforcement wouldn't get called because there was no specific or credible threat and the company doesn't have the mandatory reporting requirements that the school does.

Not only does the company not have mandatory reporting, it has a financial incentive not to piss away the man hours of it's HR team on stuff that's obviously bullshit.