Assumption, after assumption after assumption. “Just 13 million years old.” Prove it, how was it dated? How was it conclusively proven to be that age? This is what passes for real science. Nonsense.
It’s pretty easy to tell the age of a newly-formed planet. They do say in the article that the “planet” is still strongly radiating heat, likely as a result of its formation. Based on the current theories of planetary formation, we can estimate the age of the planet from the amount of radiation it emits for its size.