While there are Nokia smartphones like the Nokia 2.3, 5.3, 6.2 and Nokia 7.2 which are still stuck on the old March 2021 Android Security patch for some unknown reasons, Nokia Mobile is rolling out updates to its other smartphone models in a timely basis. The latest phone to receive the June 2021 Android Security update is the Nokia 2.4.
The update is tiny at just 33.82MB in size and only brings the June 2021 Android security patch. So, there's nothing major happening here other than improving the security of the device. If you still haven't got the update notification then I suggest you manually check for the update and install it.