I couldn’t say on that part (I’m not using docker).
Still, if the php script is ran from time to time (ideally on a scheduler), no need to use that script.
And if not, no need to use that script too.
All in all, don’t use that script. It’s a bad idea that may cause you some problems later on.
How to replace that whole script, if you ever need to:
* * * * * flock /tmp/mautic-messenger --command "/path/to/php /path/to/bin/console messenger:consume email --limit=60 --time-limit=480 --memory-limit=128M"