This is a classic thing that shady businesses do. It is completely illogical, given that if they were required by legislation to get your personal details, they should have done so prior to letting you sign up and deposit. Their whole object from the get go is to get a free option to make you lose money. If you lose, then nothing happens to your account. And if you win, then they will restrict your account, and make you KYC.

They do this with full knowledge that there is very few people that actually trust these online casinos to handle their private info responsibly.

Unfortunately, this is a risk that people have to put up with when playing online, especially at a crypto casino. No matter how reputable a company is, there is always some probability that they pull this.