The difference with this is it reduces the water available to fall further downwind, and could thus cause other issues: it's effectively zero-sum on moisture, while desalinating ocean water is positive-sum (though, yes, it has a waste issue).
Will it reduce the water available? I'm not sure either way. I've been imagining it like you're sucking the evaporated water out of the top of a half-full glass of covered water. The evaporated water is in equilibrium with the liquid water, and if you suck out evaporated water, then more liquid water evaporates. But that's just my dumb mental model.