If you follow the link to the actual item page there's no description there, just some listing data. So it looks like the descurion was removed, but is still lingering in the search system.

Do you see the yellow banner on top?

This is a header which is the same on any page on buyandsell.gc.ca. A few months ago this header looked like this:

https://i.imgur.com/wIEDeGc.png

Even on older pages (like the one with the tear gas grenades) this header will appear. Now they changed the header to something new and when the search engine will index the websites again, the Covid-19 mention on this specific page you linked will vanish.