https://nexus.leagueoflegends.com/en-us/2017/11/the-next-illaoi-skin-is/
What’s next?
Okay, now that we’ve got the skin picked, it’s time to make it! We’re aiming for release in first half of next year and, if all goes well, it’ll take about four months from when we start development to when it’s live.
We’re going to try something a little different with this one. We know a lot of you are interested in the making of skins and want to be a part of it, so we want to take you inside Riot as we bring Battlecast Illaoi to life.
We want you to be able to follow along as we make the skin—from concepting, animation, sound design, naming, and all other aspects of what actually goes into making a League skin—so we’ll post a development update every two weeks here on Nexus.
If you’ve ever been curious about something in the dev process, or if there’s anything you especially want to see, let us know and we’ll show you (if we can).
I would think that they wouldn't make promises like this if they didn't think that they could keep them, so I'm guessing either something went wrong, something came up that was more important, or they just forgot. Any way you slice it, some communication would be good.