> If you’re unfamiliar, the BUSL can easily be summarized as an eventual open-source license. That is, it’s a restrictive license that after a period of time will convert to another license, in our case Apache-2.0.

Haven’t read the license but if it works as described I’d say it is open source. It has been irrevocably released to the open source ecosphere at a concrete future date. If someone handed you a post-dated cheque would you say “I didn’t get the money” or “they haven’t paid”? If his description is accurate it’s been released as Apache it’s just in public escrow.