You can run a regular export of "Files per computer" or "Applications per computer" and compare, maybe weekly. Depending on your estate, this export may be quite big though.

Alternatively, you could work on a custom report but I am not sure the work involved would be justified, especially if that can be done in Excel directly with a bit of fiddling.

Immediately is the bigger issue you might have here. Assuming that your machines scan into your Snow system at 09:00 and the software is removed at 11:00 on a Monday, it won't appear as removed in Snow until Wednesday because it was removed after the Monday scan and won't report as removed until the Tuesday scan.

So if you remove after the initial morning scan and then don't run a manual scan, you have 2 data update jobs (at least) before you can see it as being removed from the machine.

The alternative option you have is to create a custom report as Samuel mentioned, but have it look at the Snow Inventory data instead of Snow License Manager. This won't use the SRS though so will be substantial bigger depending on the size of your environment and may be too big to even export from Snow.

If you could look for the application name itself you could use the Application installation history report. And filter on Removed and choose your time period in combination with a Last Discovered - Less or equal date. But like Liam mentioned be aware of scanning- and DUJ times.