I think the author agrees with you. What he is saying that a flexy wheel caused by a flelxible rim will behave differently from a flexy wheel having a stiff rim but too few or too light spokes. He is saying if the rim is very stiff but if too few spokes are the problem the rim will tilt at the axis defined by the hub and cause brake rub. If the rim is not so stiff, you may not notice the flex even with too few spokes, because the flex will constitute a bend at wheel's mid point, no brake rub. The "upper" part of the wheel won't be much affected. Yep, more or heavier spokes will work to fix both problems. He is trying to show that stiffening the rim may not do so. So if you are weight conscious at all, once you go with a heavy duty rim you may be screwed as you will still need substantial spokes to prevent brake rub. If you favor high spoke count or heavy spokes, you may be well served to save a little weight in the rim. That will help with the brake rub and won't hurt much elsewhere. That is, as near as I can tell, the principal learning from the article.

Robert