Hey!
Wanted to pop in here and explain what's going on with Yorick!
You're right that he hasn't received a skin since launch and his skin catalog only has two skins. We aren't ignoring Yorick, although from the looks of the amount of skins he has, it may appear that way.
For a bit of context here, Yorick needs a rework/update before the Skins team takes him under our wing and gives him more skins.
But why can't you make a skin and give him the rework after? That's the most common question I see when I explain the rework/update situation, and it's a totally valid question.
When a champion is updated (let's use Sion as an example for this), there are a ton of changes made, both in model, as well as the kit. If we were to create a skin for him now, the Champion Update team would need to rip apart the work we did to make it work for the update they create. This could mean making a new set of particles, a new model, etc. It's basically like doing the work twice. So, rather than doing that, the Skins team creates other skins for other champions while we await the go-ahead to work on a new skin. This rule also applied to Poppy (she's eligible for a skin now)! and currently Taric.
The other big reason for doing this is because we don't want players to become attached to a skin and then have it completely re-imagined. So, let's say we put out a Crazy Cat Lady Yorick skin (Rito pls), but with the rework, he didn't have a spell that used your favorite cat model. That may ruin how cool the skin is to you, which is a pretty crappy situation. So, rather than taking away things you love, we hold off on creating them until we've got a solid, shiny, new base to work from, which means the skins you purchase won't be changing any time in the near future.