I have completed the Siege of Wyrmrest Temple - but it does not show on my progression of bosses killed. I have killed the first 4 bosses, but they are not listed as showing being killed. My character is Icefreeze, Darkspear realm (EU)
Your character have done first 4 bosses in DS but in LFR difficulty. At the moment wow-heroes tracks only normal and heroic boss kills . Hopefully Blizzard will enable LFR boss kills tracking in their API and we will be able to show LFR progress.