Are there any updated Any% tutorials, or is this something I could probably learn watching the WR? The only one on SRC is outdated apparently. Was interested in trying to learn this game and arkham city.

There is not, unfortunately. A few things from the old tutorial are still relevant, most notably Bane Glide, but yeah you're kind of on your own to learn the new route at the moment. Of course feel free to ask any questions you have while trying to learn, here or in the Discord.

Is there another known way to get the "butterfly" glitch? I keep accidentally getting it just gliding around, and not with the batarang setup shown in the tutorial. Its really weird

There are a billion ways to cause butterfly gliding. It'll even just happen on its own sometimes. If the proper setup for it isn't working you're probably timing it incorrectly, you want to flick the camera up right when the sound of Batman's cape opening happens. Just keep practicing.