We cleared 13/14HC and stopped raiding for the week as it was towards the end of our last raid day for the week. We planned to extend the save after the reset however after clearing trash we found that Garrosh wouldn't spawn. We tried to soft reset twice to no avail. Garrosh wouldn't spawn.
I opened a ticket as I was the group leader and the one with the save. This was the response I got from a GM, is he right? I instantly thought he was wrong as what's the point of extending otherwise.
To clarify, we did kill all 13 bosses on heroic in that lockout.
Please do not post images, where people names/user names are visible. Edited your image.