It's not a political stunt. The people who haven't left clearly want to remain their for various reasons asides from the issues they expressed. It's an attempt from those employees to actually improve the company and address the issues they have.
It's a publicly traded company. The shareholders have a right to know if the company is being mismanaged, so they can take action to improve management of the company they own.
There is a middle ground between saying nothing and raising it to the general public. The public square is a terrible place to litigate what are effectively unsourced, one-sided allegations.
If you're leaking about something that's genuinely concerning (criminal, or just very bad and immoral), by all means, leak it.
But this seems more of a leak to make some noise, to win an argument by public opinion. Nothing but a political stunt. Not very virtuous.