This has never happened. Only people who got banned were toxic little poopstains that didn't "voice their negative opinion", but quite literally attacked everything and everyone.
I was in the server since 2020. I've personally attacked PH with questions.
I've seen screenshots in this thread where mods (not sure if it was Pasix) have been insulting users. There's always a chance the screenshots cut off the preceding context but even if the user was being rude, which they definitely weren't in the screenshot, it's hardly professional.
I've also seen them wipe out perfectly polite threads and discussions on the Steam forums, often specifically removing critical comments in a thread, and banning users for making them same. I was one of those users incidentally and I'm hardly the type to be a "toxic little poopstain," the mod that banned me didn't even bother to fill out the ban reason.
Lastly I've seen them venture outside of their little mod-bubble and go and insult some YouTube guy that posted a critical video which is just hilarious.
On the weight of it I'm inclined toward presuming you've just somehow missed whatever Discord drama has happened and the mods have probably been cleaning up after themselves so the discussions aren't there for all to see if they weren't online at the time.