It's just level 1 verification, plus you have ability to update the information too change your name and other. Some people could be fill the form with random information to bypass these and they can just update latter with real information.
Not sure where you got this information or which casinos allow this, but most casinos I’ve tried that require mandatory level-1 verification do not allow you to change your information after submission unless you contact their customer support first. They usually include a note on the verification page stating that the submitted information must be accurate and that you should not provide false details.
In any case, if you're going to complete level-1 verification and want to avoid any issues, you should provide accurate information. When they ask you to submit your documents, the details must match.