On the one hand, I'm not even running 4K yet, and it is vanishingly unlikely that I will own a >4K display within the lifetime of my PS5, so this makes no difference to me.
On the other hand, I would like to see blatant false advertising punished every time it happens. "Nobody really cares" isn't much of an excuse when they clearly thought people cared enough to put it prominently on the box. Being able to play high-end video 10 years down the line is a legitimate selling point for a gaming console that doubles as media box.