I wouldn't say "for quite some time" because just lately we had a rehash of some old ones. So no, they have not been moved or removed and are still an integral part of the game, they just don't offer one right now. They are too busy throwing overpriced and awful banners at us.
EDIT: They also have transferred skills into other things. They are being offered as a reward for HSCs, you still get some in coli (in the long run) and you get a decent skill when you buy trait boards. There's a huge focus on gems right now, for whatever reason, so maybe they plan a huge change in some way or it's much more simple another kind of powercreep.