Ion grenades will probably be a thing. But they'd probably be severely Range limited like Conc and Impact (in general, Grenades are pretty strong for their price, but the trade is you have to jog a healthy unit right up to the enemy to use them well), and all other Ion weapons so far are Exhaustible. But it's a numbered keyword. Ion 2 will be a thing in the future. Probably on a vehicle though, or like an expensive Ion Missile.

That said there's a boatload of ways to lose actions in the game, I don't see much point in being annoyed by Ion specifically. The game already is working to even out some of that though - if you're worried about suppression take a Commander with Inspire, if you're worried about Ion there will probably be something to take care of it. Engineers with Fusion Cutters to add/remove when?