I do not think there are any hand drawn maps. From what I can tell, its Adobe fresco with digital watercolor and digital copic pens. Still looks great, but there is a lot of confusion on the process.

That makes sense. The wording made it sound like it was hand drawn on a medium like paper, not a computer. To me, hand drawn implies using physical paper and marking tools. This is digital illustration which implies hand drawn input to a computer. https://en.wikipedia.org/wiki/Digital_illustration