Could this kind of texture be created procedurally? Could this kind of texture be doable in Blender procedurally? The yellow dotted line in the following reference pic is marking what I'm struggling to create.



With musgrave and noise textures I've gotten this far, but I'm unsure how to do that tattered fade between light and darker blue:
Instead of using a musgrave node as in your .blend-file, I used two noise nodes where one of them controls the scale of the second one to make the fade "grainy". I also made the ColorRamp gradient a bit softer. See the node tree below: