It's a good article. Releasing it on April fools' day is just his weird sense of humor. It's an inverse April fools' joke; everyone expects a satire, but it's serious, so that's the joke.

He has done a similar 'joke' before, releasing EIP 960 (ether supply cap) on April 1st. He said later that the joke was that people couldn't tell if it was serious or not. https://twitter.com/VitalikButerin/status/980744740277661696