Indeed, either a symlink or a shell script (which could print out a deprecation warning) would be needed.
Regarding the lightdm-guest-session-wrapper move: this is not related. Right now lightdm-guest-session-wrapper and gdmflexiserver are both installed in /usr/lib/lightdm/lightdm/. /usr/lib/lightdm/lightdm is prepended to $PATH so that user programs can find LightDM implementation of gdmflexiserver. This means lightdm-guest-session-wrapper is added to $PATH as well. Installing it in /usr/sbin prevents that.
I can rework the MR to only change the installation dir of lightdm-set-defaults if you prefer.
Indeed, either a symlink or a shell script (which could print out a deprecation warning) would be needed.
Regarding the lightdm- guest-session- wrapper move: this is not related. Right now lightdm- guest-session- wrapper and gdmflexiserver are both installed in /usr/lib/ lightdm/ lightdm/ . /usr/lib/ lightdm/ lightdm is prepended to $PATH so that user programs can find LightDM implementation of gdmflexiserver. This means lightdm- guest-session- wrapper is added to $PATH as well. Installing it in /usr/sbin prevents that.
I can rework the MR to only change the installation dir of lightdm- set-defaults if you prefer.