preinst is in wl 2.14.0-12.
This file is a maintainer script. It is executed when installing (*inst) or removing (*rm) the package.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11  | #!/bin/sh 
set -e
if [ -f /etc/emacs/site-start.d/50wl.el ]; then
  cat /etc/emacs/site-start.d/50wl.el >> /etc/emacs/site-start.d/65wl.el
  rm -f /etc/emacs/site-start.d/50wl.el
fi
if [ -f /etc/emacs/site-start.d/60wl.el ]; then
  cat /etc/emacs/site-start.d/60wl.el >> /etc/emacs/site-start.d/65wl.el
  rm -f /etc/emacs/site-start.d/60wl.el
fi
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