I do remember that some Rioter(s) have stated that the primary thing the skin team pays attention to isn't who hasn't gotten a skin for while but nor is it who is a popular champion (I mean Galio got that Debonair skin not too long ago.) What they choose to do is based on how cool an idea it is for the character. Child genius, gifted in hextech engineering creates energy projectors like some techno-fantasy Tony Stark of the Middle-Ages and creates a giant robot version of her best friend. That's cool enough of an idea to be used for a new champion! Let alone a skin.
And on the topic of cool skins, Kha'zix is going to be getting this one that makes him look like a Mantis which looks pretty good, and I believe that Kha'zix was on the "owed skins" list, Kennen too, so they are getting to it eventually.
Although, Yes, it really does suck that for some reason Riot is slower at getting to things than pretty much every one else.
It's a bit more complicated because this has a lot to do with drop-rates. And it's because of drop-rates I have to conclude that it is neither a free skin nor a skin you can just simply get by playing the game.
Hextech Annie is obtained through Rare Gems that occasionally drop in the chests and it requires 10 of them. I ended up coming across this video by a Jeremy "Gaming Curios" somehow and he did a PBE video where he opened 1,000 chests. At the end of it, he ended up getting a Rare Gem in about one out of every twenty-one cases. So at current drop-rates, that means that a person would either A: not be able to get this new skin or B: have a metric ton of patience, save every gem from their weekly cases for years.
That's the "free" route; there are also Promo cases on the PBE store. There is among the bundles one that comes with a Rare Gem and that looks like the route a person would have to go with if they actually wanted the new skin without spending an unreasonable amount of time waiting for it. That makes it less of a skin "you can't even buy", like I said, but they are called "Promo Hextech Chests" which means to me that they'll only be available for a limited time and they really are the only way to get this skin.
We don't know the Live prices of the bundles, but it looks like there is no way this skin is going to cost near ten bucks. So I understand the reasoning behind giving the promotion to a champion who has more skins, when most people are not going to be able to get it.
Despite that, I will say that this scenario sucks as well.
Addendum: In searching for that person, I also found this thread where apparently Jeremy opened 10,000 Chests and the drop-rate for Rare Gems in that was lower by one percent, so about 6 more chests per Gem.
