It would also be fair to say they didn't skip any generation of processors with that gap in updates, they merely sat out the first two years of Intel shipping Skylake five years in a row.

And in the meantime, they did use those first two years of Skylake for the 12" MacBook; the next update to the MacBook Air was after the last update the 12" MacBook ever got. For a while, the 12" MacBook was the more premium, thinner and lighter alternative to the MacBook Air with more advanced technology (and could plausibly have been construed as the intended successor to the MacBook Air), then in 2018 they merged back together with the introduction of the first MacBook Air with a Retina Display.