You are creating a galvanic cell so if it gets wet you will definitely get corrosion. Luckily the aluminum parts are the ones that are more anodic and corrode so you wouldn’t be ruining the frame.

If the lubricant isn’t conductive it would at least help.

https://www.mcfeelys.com/galvanic_corrosion

Bare aluminum seatposts love getting stuck in steel frames. I assume headsets will get stuck, too, though I have less experience with those. Using anodized aluminum parts helps a ton. The anodized layer on the surface is mostly inert and prevents further corrosion.