When we delete any segment, it shows the notification that it could have been used in dashboards but it doesn't show the name of dashboards using this segment.
Ideally, it should display all the dashboards which are currently using a particular segment so we can easily do segments cleanup whenever required.
Thanks for submitting this idea! We've heard this request a few other places, and agree that it would be a great addition to the product. We'll keep an eye on the idea for votes and comments going forward.