While this policy isn’t ideal, it seems a bit better than simply downgrading Row 4. The old method would downgrade someone to Y who purchased a full-fare F ticket and leave an upgrader in F. That hardly seems like a smart strategy.
Also, as those of us in Alaska know, we are hub captive here. Forgive me as this sounds more sarcastic than I intend: do you consider the 1x daily seasonal flight on Delta that doesn’t restart until June to be a reliable alternate to Alaska?