Deprecation notice for “dynamic properties” in PHP 8.3 in spite of documented exemption / workaround?

As of PHP 8.2, “dynamic properties” have been deprecated and will be removed in PHP 9.0, see https://php.watch/versions/8.2
Before refactoring dynamic properties into a WeakMap, there are supposed to be a few exemptions from the deprecation (cf. the above link), and one of these exemptions are classes with __getand __set magic methods. And indeed, while on PHP 8.2, my code produced no deprecation notice.

However, it seems that after upgrade to PHP 8.3, the deprecation notice is issued in the body of the following, i.e., in the very implementation of those exempting magics:

 public function __set($property_name, $value)
 {
    $this->$property_name = $value;
 }

On https://php.watch/versions/8.3 and https://www.php.net/releases/8.3/en.php , I find no hints that the exemption was removed.

Question: Is this a negligience in the PHP 8.3 documentation, or am I missing some reason why “my” __set(and similar __get) are not good enough to count for the exemption?

(Meanwhile, I added the #[AllowDynamicProperties] to the class, but am still curious)