Don't ask how I know but this was a 'temporal marker' as Clif High might say for positive change. I think it was delayed because the of the dodgy money flowing through Marijuana farms.
It's looks like they are going down the 21st Amendment path, used at the end of Prohibition of alcohol. This is sensible. You can have dry towns and states can make the rules concerning cannabis.
I had a vivid dream about drug dealers in Detroit changing their ways, going legit and becoming real estate tycoons off this using hemp as a construction material. No kidding. It's big.