As mentioned by @antikythera the key word is Beta named after the second letter of the Greek alphabet and following the alpha phase of software. Beta testing is performed by users on a real environment and there are likely to be some bugs encountered. Whilst some users are fine with testing and experiencing new features first, others who only have one device which they are reliant on may be more wary.
Anyway Google devices have access to the Beta and final versions earlier than for instance Samsung. It is envisaged that the final stable release may hit pixel Devices in September/October, Galaxy Devices would be a bit later.
See more here https://www.techradar.com/uk/news/android-12-news
I do not work for Samsung or make Samsung Products but provide independent advice and valuable contributions.
My Device- S21 Ultra 5G ( SM-998B/DS ) CSC= BTU , 12GB/256GB
One Ui 5.0,Android 13 .