[emodendroket]

> I wonder if/how they will unify them or phase some of them out.

They pretty much never phase anything out because they're serious about backwards compatibility (which frankly I consider refreshing in this world). I mean they've even said at some point like "yeah, the delegates are unfortunate because they're just a more awkward syntax for what the lambda functions do but we're not going to get rid of them because people have used them."