Hi Colin,
no worries, it says in the wiki too, this file is only as sort of "last reserve" for those that cannot/dont want to set up a CRON job and use Cumulus, which can otherwise not run the script at regular intervals.
I basically wrote the documentation and included this file at a time when I havent yet discovered the free CRON service, which I now recommend. So at that time, Cumulus could only be updated using either CRON run by your own server or your webhosting provider and since not all providers allow imnutely crons I needed a way of solving this problem.
Curl is a little program that can be run by standard Windows Task Scheduler and so you can perform the updates this way.
But I guess that now that I found that free service there really is absolutely no need to use this, even for Cumulus users.
So dont worry, the file is not used by the actual template at all.