"which should not exist under leading planet formation theories"
Every time I read that something should not exist based on current understanding or theories, especially in the field of astronomy, I cry a bit.
Falsifying a theory is a nice thing and assures us that empirical science is working as intended, yes? Or sometimes laypeople were overeager to label as “theory” some things which enjoyed status as mere hypothesis, or conjecture, or proposal, and so update/reform the models and take baby steps again.
I am skeptical that “planet formation” is a type of subject where we could entertain any theories at all, on the human timescales we can handle.