If that's part of their marketing strategy they're not actually leaks. I know for a fact it wasn't like that for TMNT, so it's neither here nor there.
Stern can't go to Facebook and say "this podcast is full of meanies who criticized our product, ban them". They have no standing. Facebook don't care that you did an episode on playfield dimples and topper DLC.
They can however go to Facebook and say hit them with a copyright strike for posting internal images that weren't released. That's basic stuff, simple to prove. So if the podcasts want to protect their precious Facebook pages they know what the risks are.
The rules are all clear. You want to not get strikes, don't post leaks. Sit on them until release and use that time to think about what you want to say, like normal journalists who get early access in return for respecting an embargo do.
You want to get free swag then support the IFPA, you don't want to support them then skip the free shit. Again, basic rules. IFPA and Stern scratch each other's backs, they both benefit, you can get in on that or not.
I haven't bought a Stern game in years, and I'm not carrying water for them, it's just about being responsible for your own actions.
I used to do early code testing for Stern, until they saw me post something critical about them on Pinside once, and cut me off. Why wouldn't they? I wasn't mad, I said what I said and shit happens. They banned me from their factory because I took a gig with Heighway and was a competitor. Again, their right, so what. They asked me stop doing translites with trademarks from their licenses on them. Their right, I didn't throw a fit, I was playing in their sandbox.
Just be an adult about the decisions you make, and how it affects you.