If your lateral true is only out 1mm (which is more/less considered the allowable standard) I doubt this is the cause of your wobble. Many bikes will exhibit the hands-off wobble you mention and it is something you can just live with by not taking your hands off the bars for long. (All two-wheel vehicle front ends have a natural resonant frequency which manifests itself in a diverging wobble.) Older, less-rigid, more-worn bikes seem more susceptible in my experience.

I disagree with the cited reference that says bearings have nothing to do with the problem. While it is possible to have perfect alignment and bearings and have a wobble, it is also possible that a wobble is much worse when bearings are loose. One thing to certainly check is to be sure your steering head and front wheel bearings are up to snuff. Any play there will aggravate the problem in my experience and I have had bicycles with a wicked wobble that were more/less cured with a properly adjusted headset. And wobble or no wobble, you want these things to be adjusted and working properly regardless.

- Mark