Which is one of the issues with a high-speed deal like this. If you want to see real deep and detailed information, that is going to require more time and negation and NDAs and such. Companies can't just violate their privacy policies and give out data to whoever. So if the prospective buyer wants access to user data, it could require jumping through some hoops. They might not even get to see it directly, it might have to be a third party who has some duty to keep things private.So have the lawyers for Twitter, and they've said he was demanding information he wasn't entitled to. Obviously, Twitter's lawyers are biased, and so is Musk, but I'd bet their lawyers haven't been fined by anyone for untruthful statements, like Musk has (although, sure, the fine was accepted without admission of the allegations).
If you want to see the contract, it's publicly available here; section 6.4 is the part in question with regard to access to information.
Regardless it isn't something you can not include in the contract, and then pitch a fit about it later.
Now we'll see, maybe the court will agree with Musk, but I kinda doubt it.