Expressing interest in an AK makes it appear on the "recent changes" list
When a user clicks the "express interest" button on the AK's detail view, it is then added to the "recent changes" list on the overview page: https://ak.kif.rocks/kif485/
I would not count the change in the number of interested people as a fundamental change in the AK itself, so I would expect that this would not make it appear in the "resent changes" list.