Looking back at Leaked Skins
Looking back at this supposed skin leak, let's see how credible it could be.
First off, both Sejuani and Tahm Kench DID get skins for the year of the pig. So that they were right about.
On the other hand, their description of Sylas was completely off, what with the lifting and tossing of the enemy, and the "AOE table flip". Considering that this "leak" wasn't very long ago and that it is highly doubtful Sylas could have had such a large kit change, this is extremely questionable.
However, we can't completely discount this, unless the Kayle and Morgana rework descriptions are also completely off. K & M will probably be the next in line after Sylas, so...
I do kind of hope most of these skins are real and will get through concept, although I'm not entirely sure how a Legendary "Anti Star Guardian Syndra" would work considering her existing skin and lore.