Not good. Stripe rejects anyone even close to the regulated cannabis space (with no room for appeal) but PayPal will accept these tranctions. So, this would put a non-zero amount of businesses (that don't even touch that deadly, deadly plant) in a tight spot with this monopolisation of the industry.
Someone new will arise to fill the market gap if there is demand. Saw it firsthand here with the Marijuana industry in Michigan shifting around payment providers to accept credit card transactions after it was legalized. A lot of hoops had to be jumped through. I think it still has the potential to be bad, but it does give opportunities.
I don't think anything would change. If Stripe's underlying providers (banks) aren't involved then their requirements would not apply.
Stripe doesn't want to reject anyone, but their banks/underwriters do not have a limitless appetite for risk.