Copaslip (trade name) or a generic copper based anti-seize compound probably won't do any harm, but Sapim's testing claims that their anodised 7075 nipples are actually more corrosion resistant than brass. I think on balance I'd take something with better lubricity.
Have some alloy sapim polyax nipples I'm building to some cx ray spokes soon ($$$).
Will some wet chain lube meant for XC use be good enough to lubricate threads enough to stop seizure?