No luck trying to reproduce the bug in a VM this time even though I succeeded last year (bug #1136776). Checking /usr/share/YaST2/modules/Users.pm, the patch in comment 2 of #1136776 has not been applied, i.e. the code that caused the bug is present on the install media. There probably are some difference in the installation choices, e.g. last time I probably partitioned manually from scratch while this time I modified the proposed partitions to add /home. This may be why the bug is not triggered this time. To decide how to modify the "most annoying bugs" list, one would need to know whether this bug only comes in after installation or can also be triggered during installation while creating the initial users because instructions "run updates before creating users" only work for after the installation.