EK will operate them side by side, at least for a bit.
There is also much talk of EK
and the likes of LH
pushing for a 777 freighter.
The 777-200LR will make an outstanding freighter platform, and will fill a HUGE gap - the 90t freighter market - caused by the exit of the MD
That being said, the A340-500 and the A340-600 would also make good freighters.
The 744's niche will be for long cargo that must be loaded via the nose.