I guess if your software is stable and 'finished' enough not to be updated often then it would be good if you have an established communication channel (like a website or a GitHub page) that will periodically come out with, well, 'news updates', since it is true that most users are conditioned to expect some kind of update/activity surrounding their software.

Besides any moderately complex software will probably have enough bugs to require updates now & then for years, even if no new features or added. Not only bugs but often the underlying platform changes/breaks, needing workarounds or rebuilds.