Which was never the point of the system in the first place. As a poster above showed, the language describing rider switch says the second parent or guardian is supposed to board with others who did not ride previously.
You view this change as tacky, which it may be from a timing perspective with paid Fast Passes on the horizon, but I personally find not observing basic line etiquette to be tacky. True, it is generally no skin off my nose when it happens, and I’m certainly not going to confront someone over it, but you are prioritizing your time and experiences over those of others when you do it. Allowed by Disney or not, I think it’s inconsiderate, even if it’s mild and falls under the “tolerably inconsiderate and totally understandable from a parent’s perspective of wanting more for their child” category. Still, you’re inflating the wait time of others and may be making them late for a reservation or reducing the total number of rides they can visit in a day. Minor inconveniences to them in the grand scheme of things, but inconveniences nonetheless that I would personally avoid by abiding by the spirit of this rule rather than taking advantage of it in the way that most benefits me personally.