When I first saw this line, I chuckled bitterly to myself. Siege is melee friendly? This got me to wondering how we define melee friendly. Is it just the ability for melee players to contribute solid DPS? Because by that standard, Siege has some good fights for melee - the Fallen Protectors, Sha of Pride, Galakras and even Spoils of Pandaria are certainly fights where melee DPS can contribute a good deal of positive damage to an encounter. Phase 1 Garrosh is a place where melee with good cleave potential absolutely shines. So by that standard, a case could absolutely be made that Siege is melee friendly.
They realize raids need to be more melee friendly in the future and they are working on it, but they feel that Siege of Orgrimmar is one of the most melee friendly raids in recent memory.
Now, in terms of melee staying alive without making the healers hate every single one of them that the raid brings to the party? Siege of Orgrimmar continues in a grand tradition of blowing up the melee. By that standard, SoO is absolutely not melee friendly.