Hi Fred,
It's not threaded, it's just a plain section of axle used to space the hub away from the fork, but it looks like the Edge has the disc mount spaced further from the fork leg to allow for the larger fork tubes used on suspension front forks.
You can see on the following pictures that my front Smart Pie has the disc mount slightly closer to the fork:
And the tyre is nicely centred between the forks:
But I guess some customers may have experienced clearance problems if this motor was fitted with a brake disc and installed on a bike with larger diameter suspension forks:
If GM had assembled the wheels with the rim correctly positioned centrally between the dropouts it should not have caused a problem.
I would first try to centre the rim by adjusting the spokes
(loosen all spokes on the R/H side by two turns and then tighten all spokes on the L/H side by two turns, and repeat if required) to see if you can improve the situation. If that didn't work, I would place spacer washers on the R/H end of the axle and spread the steel forks slightly with a car scissor jack to accommodate the increased axle width.
Alan