I can't imagine EZ connectors corroding while standard ones being fine. True that EZ is exposed on both ends vs just one, but to say that the jacket's end somehow hermetically seals the inside end of the connector is simply not true. To that end corrosion would be more prominent on the end with stagnant environment where air slow is reduced.
Besides, its the flat part of both jack & plug that make electrical connection.
And for god sakes, where are you guys installing those cables where Cu oxidizes to the point where you're having failures?