There is no average. Figure within 48 hours you'll have a reply. I'm not sure where you got that email address from, but I've always emailed them and got a reply usually in 24 hours
I received some of my dsdplus updates from the dsdplusInformationMinister email back in 2019 but that was it. All the others came from the email in the notes or readme file like
@BM82557 listed.
Not a one of my dsdplus files have the odd dsdplusinformationminister email address listed in them and I've subscribed to the program for a many years now and always keep every single file sent to me or downloaded from the site using the auto update used these days.
In my case, I'd used a work email when I originally subscribed to dsdplus but retired in 2018. I emailed the dsdplusfastlane email and requested my account email be changed to a different personal email I use. I received a reply in under an hour for that request.