Generally the exchange authorities do not easily freeze the funds of their customers or users, but sometimes for special reasons they can temporarily freeze the funds of the customers.
Personal information ,If a customer has placed the personal information wrongly i.e. if he has submitted wrong information while doing KYC, then the exchange authority can freeze his funds temporarily.
Illegal funds,If a user transfers funds from an illegal source, the exchange authority may freeze the user's funds permanently.
Location,Many times, if the user's location is in the restricted list of the location of the exchange, then the exchange authorities can temporarily and permanently freeze the funds in the user's account while transferring funds to that location.
@OP, According to the information provided by you, the female user has committed any illegal activity against the Coinbase rules or against the terms and conditions under which the exchange must be used. Because of this, the Coinbase authorities have permanently frozen the user's account funds.
I agree with you, for unknown reasons people are spreading FUD against them and all other reputed CEX but they are very unlikely to seize your funds because you're using them to play at a casino or to buy adult content or medications. They can close your account, but they are very unlikely to seize your funds, otherwise we were seeing many complaints against that in the reputation section.