I was an intern at a large museum in NYC in 2017. When I visited the gift shop, I found a book which was published when Pluto was still a planet. It was the same book I was given when I was little, ~15 years ago!
It was thought that we would find a huge number of dwarf planets shortly which would make list of planets untenable.
However, in the years following, we really haven’t expanded the list significantly.
It probably would have just been better to have added these “dwarf” planets to the list of planets rather than come up with a convoluted reasoning about clearing their environments, which isn’t even technically true for Earth.