The honk is undeniably a strong signal, and has already trained me in ~2 days to immediately check my toolbar.
But when one has a lot of PRs in flight, it can be hard to tell what the honk was for at a glance.
A desktop notification could help make it clear what changed, and give a direct link to open the PR in question.
I don't know if there are cross-platform libraries to deal with those, or if such a standard thing even exists on Linux or Windows, but it'd be nice for me, a troglodyte Mac user.