Yes, if they came out with a pancake 19mm f2 or 20mm f1.7 or something like that at a good price then it would be very popular, I think. The pancake Panasonic 20mm f1.7 shows the small size that is possible. I briefly considered the 19mm f2.8 because the FL was good for my purposes, but the f2.8 is a bit slow and the lens is large. I got the 20mm f1.7 instead which is smaller and faster.
I am hoping that Sigma and Tamron continue making lenses for mirrorless to give more choices and competition.