FYI, the cargo mat from my 2015 Leaf fits in the 2019 Leaf. Sort of. The front two corners aren't covered. The back two corners (not pictured) fit, but the right (passenger) corner is raised a bit so the mat doesn't lay down quite right in that corner.
The front seat floor mats also fit. The driver side is right on the money, but the passenger side isn't perfect. The fit is good enough that I'm not going to order new ones.