purge-kernels question

If in /etc/zypp/zypp.conf multiversion.kernels = latest,latest-1,running is set and I run purge-kernels will it make adjustments to the grub2 menus or do I also have to run the grub2-mkconfig routine?

No, openSUSE systems are virtually maintenance-free.

Grub2 makes use of a link to the current default kernel and that link is automatically adjusted. Here is part of my /boot directory:

lrwxrwxrwx  1 root root       31 Jul 24 09:10 vmlinuz -> vmlinuz-5.3.18-lp152.84-default
-rw-r--r--  1 root root  9052336 Jul  7 14:03 vmlinuz-5.3.18-lp152.81-default
-rw-r--r--  1 root root  9060528 Jul 21 14:20 vmlinuz-5.3.18-lp152.84-default

No. it does not. At least in default configuration as shipped by openSUSE.

and that link is automatically adjusted.

This link is adjusted during kernel package installation/removal, not by grub2.