Why is the VirtualBox kernel module no longer supported in 13.2?

If you attempt to install virtualbox-ose-kmod in release 13.2 the message

..

To avoid crashes due to kernel incompatibility, this module will only
load on FreeBSD 13.1 kernels.

will be displayed, and it is not able to be loaded into the kernel with kldload or at boot by adding vboxdrv_enable=YES to /boot/loader.conf. Does anyone know why this is?