plymouth-theme-fade-in warns on removal

Binary package hint: plymouth

The following warnings were found by the auto-install-teste in a clean chroot:

# apt-get autoremove plymouth-theme-fade-in
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
  plymouth-theme-fade-in
0 upgraded, 0 newly installed, 1 to remove and 7 not upgraded.
After this operation, 139kB disk space will be freed.
Do you want to continue [Y/n]?
(Reading database ... 14344 files and directories currently installed.)
Removing plymouth-theme-fade-in ...
update-alternatives: warning: alternative /lib/plymouth/themes/fade-in/fade-in.plymouth (part of link group default.plymouth) doesn't exist. Removing from list of alternatives.
update-alternatives: warning: /etc/alternatives/default.plymouth is dangling, it will be updated with best choice.
rmdir: failed to remove `/lib/plymouth/themes': Directory not empty
rmdir: failed to remove `/lib/plymouth': Directory not empty
update-initramfs: deferring update (trigger activated)
Processing triggers for initramfs-tools ...