Not sure it matters does it? Might as well have that one on there than a thinner one; it'll be the same strength if the same number of threads are engaged.
M12 x 1.25 fine thread pitch , they are all std pitch size for ebikes so one will proably have to buy spare nuts and machine thinner if it really bothers you.
A generic M12 is 1.75 pitch so don't use them.
Leave it as it is, it will prevent the axle thread from damage and x threading.