Why have the following skins been unoficially black listed and never been put on sale?
■ Jan. 10th, 2012: Dragonblade Talon (975 RP), Guqin Sona (975 RP), Jade Dragon Wukong (975 RP), Dragon Fist Lee Sin (975 RP).
■ Feb. 14th, 2012: Heartseeker Vayne (975 RP).
■ Mar. 20th, 2012: Wicked Lulu (975 RP).
■ Mar. 23rd, 2012: Jurassic Kog'Maw (975 RP).
■ Apr. 1st, 2012: Fisherman Fizz (975 RP).
■ Apr. 2nd, 2012: Mafia Graves (975 RP).
■ Apr. 6th, 2012: Battle Bunny Riven (975 RP).
■ Apr. 18th, 2012: Blood Knight Hecarim (975 RP), Reaper Hecarim (975 RP), Warlord Shen (975 RP).
Seems like an awful long time with never having had a sale since they have been introduced. Is there an official policy to black list some skins? or has this just been a very weird and unfortunate coincidence?