They're saying that the spoke is thicker at the j-bend than most other spokes on the market and thicker than what most road hubs are drilled for.

e-mail Phil Wood and ask about this. (it's the hubs you're worried about, not the rim)
I know my DA track hubs won't take them. I was going to try the same AlpineIII / Open Pro setup that you're talking about.

Heavy duty mountain hubs are generally drilled for larger spokes, road hubs are not. Phils might be.
I've had to talk several people out of Alpine III's b/c their hub wouldn't work.

If they don't work, no biggie. Just go with whatever heavy duty spokes will fit (DT only please!!!). There's lots of argument about straight gauge vs. butted, but spokes generally don't break in the middle, they break at the j-bend where they're all the same diameter (except for Alpine III's).