Silly me!
I’d expect that the RINGS form into planets, rather than the gaps...
“The largest gaps likely contain protoplanets, which form by collecting gas, dust, and small meteoroid fragments, gradually clearing their orbit of that debris.”
The protoplanets gather dust as they orbit the star, creating the gaps. Some new math shows that they tend to sit just on the edge of a ring and actually act to compress the rings, which in turn may form additional planets.
The gaps are where ring matter used to be but got hoovered up to congeal into a planet.