I could write a book on this. I don't work in legal, but we'll call it legal adjacent and I have a fair amount of insight here, especially because I've worked on dozens of very secret projects with high profile names and reviewed hundreds of legal contracts.
Contracts are typically years in the making. Some are easy, and some are hard, but they require a lot of pleasantries, back and forth, and negotiating. Even a tiny change to contract language requires all parties to review them, and it's not just lawyers. It could be dozens of parties on both sides having to review a change. That means a few sentences can take weeks while it gets through email or Adobe Sign or whatever, and you have to repeat this *every time you make a change*. Oftentimes, no one intends for a contract to take forever, but you simply find yourself there, and work proceeds in the background on good faith while the lawyers hammer it out because you can't always wait for the lawyers to choose "must" to "shall". Sometimes, this doesn't work out very well if people make assumptions, like Universal Hollywood producing merch before the ink was dry, so that's why having a good relationship with your rightsholder is so critical. People always talk about how being connected is so important, and this especially matters in contracts because the rightsholder is trusting someone else with their property.
That really goes back to your comment about rightsholders being drama queens. They typically aren't. Imagine for a second that you manage an IP. That IP might be something important and valuable. It might be central to your revenue stream. Maybe you built it from the ground up. You want the tone to be authentic. You want the messaging to be right. You want the timing to be right. You want the news cycle to be right. Maybe the property hasn't been relevant in a long time and this is a chance to make it popular again. And then the third party leaks your surprise all over the news in an unfinished state (like the FNAF trailer). Or they build a giant Mindflayer out of paper towels. You're devastated. Trust is broken. You may suffer mockery or revenue impact. Why would you trust that company again? You yank the contract to send a message because leaks remove your ability to control things. It's like reading a synopsis of a TV show or movie before it comes out. Without context, you can reduce Batman to "a vigilante in a bat costume beats up criminals" and that doesn't account for the tone, music, or cinematography, and maybe a few people (unfairly) decide that's not their cup of tea. No one sets out to make something awful (for the most part) and it's fair to want something to be judged by the final product, not what people read third hand on a forum. There's just a lot of reasons why a rightsholder would be frustrated if someone licensing their property doesn't treat it with respect.
I'm not criticizing anyone here for leaking anything (I'm here, aren't I?), because I think the people here are very aware of all this, but it's fair to say that no one should be surprised if leaks annoy the rightsholder.
