Running into the same problem on a brand new, out of the box 7490. Every reboot, Dell Command Update is telling the user that the system has been updated. Going to uninstall Dell Command Update to try to get rid of the alert.
The other thing I find unusual is that every time I open Command Update, it tells me it last checked "Never" and it last updated "Never". Clearly un true as it just ran, scanned, and updated a week or a day ago.
I've had DCU on many laptops over the years and so far only this latest 3.0.1 version is giving me trouble. All the other DCU installations do NOT notify me constantly, and the "last update" and "last installed" has always shown me the proper time it last checked.
On a related note, in the past month or so, the latest version of Dell's utilities have been pretty crappy. Dell Digital Delivery (the new one) hangs on all my laptops forever, just sitting there with a spinning circle when I try to run it.
Dell Power Manager and Dell Trackpad Software now stupidly needs the Microsoft Store to download the applications, which is hilarious because Windows 10 Long Term Service Branch doesn't even HAVE the Microsoft Store.
Dell XPS 13 9370, in-service April 2018. The "The system has been updated" notification pops up after every startup whether **bleep** down OR SLEEP mode. It is not an annoyance unless the taskbar icons are needed.
The notification started about May-June 2019. This must be the result of a Dell software change. Hopefully, this helps the developers find the cause and correct it.
My solution is to uninstall the 3.xx version that comes with the laptop, and then reinstall the 3.0 version which you can still find on Dell's site. The 3.0 version doesn't have this problem. If I remember correctly this 3.0 version is strangely hidden on Dell's site so it may take a bit of screwing around to find it. I keep a copy on a thumb drive because I was tired of trying to find the program on Dell's site.
You can also find and use any of the 2.xx version which work fine and don't give this buggy notification. A brand new out of the box 7490 ran Dell command Update 2.xx just fine the other day.