^Maybe because there is a pandemic happening and gangbangs require multiple people to be in the same room at the same time and shooting those kind of scenes is really dumb.
I suspect that pat is right that shooting has stopped because of the pandemic. Kink has a reputation for being conscientious and careful (not a reputation that Legal Porno shares) so it makes sense that they have stopped shooting gangbangs until it's safe again.
In my opinion Kink is now basically a dead/dying site and it started long before Covid was on the scene. In fact I would say that it started about the time Kink had to leave the Armory in San Francisco. They had to find other places to shoot porn and I think the Armory was a huge part of what made Kink what it is. They did a decent job of keeping up the illusion that they could keep on shooting their brand of porn but too often you could see that they what came after that was but a shadow of their previous greatness.
These days they mostly shoot solo stuff and offer remastered older videos.