The idea was that the change would be an improvement, with better tracking of unread threads. Since most people don't see it that way, the original behavior has been restored.
Sorry for the disruption, and sorry kcbrown and everyone else who liked the change.
“The egg hatched...” “...the egg hatched... and a hundred baby spiders came out...” (blade runner)
“Who are you?” “A friend. I'm here to prevent you from making a mistake.” “You have no idea what I'm doing here, friend.” “In specific terms, no, but I swore an oath to protect the world...” (continuum)
“It's a goal you won't understand until later. Your job is to make sure he doesn't achieve the goal.” (bsg)