I follow and bookmark quite a lot of posts, so I can find them easily, re-read them etc... but I usually follow them so that I can be notified about actions on that post. There are inbox notes of almost every kind now, closed/reopened question notes among them, but there is no notification when a post I've followed is removed from the network.
Having an inbox notification about followed-post deletions would also be very helpful on sites where I don't have 10K+ reputation, so I'll know why a post I followed has mysteriously disappeared from my "Following" tab.