Schedule 1 -> banned from the financial system.
Schedule 3 -> OK to use the financial system.
How the DEA schedule and the financial system interact is still unclear. The important part is that once regulations are updated weed businesses won't be restricted from access to the financial system. There may be some more regs around that access, but I'm sure they'll be worked around.
This is not true.
Here is a legitimate business selling schedule 1 drugs: https://www.caymanchem.com/product/10801/mephedrone-(hydroch...
Regulatory Information: DEA Schedule I
With a schedule I DEA license, you can buy this product, and the manufacturer can deposit your money into a bank.
That's why I'm not sure moving marijuana from schedule 1 to 2 or 3 will really change much from a banking perspective.
Marijuana dispensaries will still be violating federal law, no different than if they were selling sleeping pills illegally.