Consider the lowly paddle. It really doesn't care what words we use to describe what it does; it may actually predate language and has a grandfather clause. But it can help resolve this apparent (but in fact non existent) difference of opinion with a little hands-on experience.
If we hold a paddle the wrong way, it slices through the water easily, at great speed, with little contribution to the forward motion of the boat we are sitting in. It clearly exceeds its theoretical hull speed. Rotate its handle 90 degrees, and it resists moving through the water so much that the boat we are sitting in starts to move. That happens because a bunch of water piles up in front of the paddle, and we leave a hole in the water behind that fills in as the water around the hole overcomes it's inertia to respond to the laws of gravity. Interestingly enough, the boat we are sitting in moves as if its being pulled by a force equal to the amount of water that is piling up in front of the paddle. If we pull the paddles with much more force, we don't really go faster, we just make a longer hole in the water behind the paddle.
Now if, by mistake, we let the paddle stretch out to the side, it suddenly darts to the surface and skips across the top of the water. Not much force gets applied to that imaginary rope
pulling the boat we are in. That is because the paddle rose out of the water to skip over the top. The paddle is moving faster than the water can get out of the way, (not pushing a bunch of water in front of it,) so it climbs over the water like a snow ski over heavy powder. Inertia has more effect than displacement.
A narrow boat, with a fine entry, is a paddle going sideways. It doesn't push much water aside. A relatively short, fat boat pushes a lot of water aside, creating a bow wave. The dip behind the bow wave is the hole behind the paddle, and the stern wave is the over-reaction of the water responding to gravity. If a catamaran
slices through the water without pushing very much water aside, there isn't much of a bow wave, so there isn't much of stern wave, and so on. But since the laws of gravity aren't confused by an extra hull or two, the catamaran
is still floating based on how much water it displaces*. But by going much faster, its dancing on top of a longer hole in the water. So is it planing like a snow ski? Kinda, but its not riding on the top of water that can't get out of the way fast enough. Is it displacing as much water as it weighs? Kinda. Is that what is happening when a B42 First gets the wind in her teeth? No. This is more like that semi-displacement hull with a big engine
climbing over its bow wave, which reduces the bow wave, which makes it easier to get over its bow wave ad nauseum. That's planing , even if it isn't doing thirty knots.
Is anybody breaking the law of hull speed? No. It has been rescinded by Wikipedia, an authority by consensus
*Which is more important, being skinny and cool -looking, or just not carrying around its own weight in lead dangling way under the boat in structure with surface, induced and parasite drag?