Well, I might be wrong. Let's do the math out loud. Double check my work in case I miss anything.
pregen
130/80-16
130 x 0.8 = 104 mm tire height
104 x 2 = 208mm = 20.8 cm = 8.18 inches of sidewall/diameter
8.18 + 16 = 24.18 inches final diameter
new gen.
130/70-17
130 x 0.7 = 91 mm tire height
91 x 2 = 182mm = 18.2cm = 7.16 inches of sidewall/diameter
7.16 + 17 = 24.16 inches final diameter
I'd say those are close enough to be considered the same.