Matt has mentioned that he can’t control how Google decides to rank .com or .org plugins page in a search, so he’s heavily impying that .com plugins pages outranking .org in search enginers is unintended.
But the fact is the WordPress.com plugin browser has existed for 8 years, but it was only opened for non-logged users (and search engines) about a year ago.
And since they made them public, Automattic has been actively working on improving SEO for the .com plugin pages:

https://github.com/Automattic/wp-calypso/pull/76496 (one example of plenty of SEO-related PRs on Calypso’s plugins pages)

So, honesly, I don’t know how he could explain all that SEO work without being an active attempt by Automattic to divert organic traffic from the .org repo towards the (premium) plugin pages of WordPress.com.