Another reason this may work is because when you zone, you are actually in the Eye of Eternity, it even says you are on the mini map and everything. So I am wondering if this is because the server gets confused on whether you are in the DS Eye of Eternity, or the real Eye of Eternity; so when you cast Have Group, Will Travel at the beginning of the real Eye of Eternity, it thinks you are in the DS Eye of Eternity, and allows you to summon the LFR group there. Thats just my two cents on why this probably won't work for any other raid. (Not saying it won't, just probably since I have not tested this myself with any other raid.) Hope this makes sense!