So it’s still illegal at a federal level, but the department that would ostensibly enforce that simply let it be known that they would defer to state law and not prosecute when state law legalized it.
But since it was never actually legalized at the federal level, it’s little more than a gentleman’s agreement (which could be pointed to as a valid defense if someone was prosecuted federally). But since the directive came from the executive branch, it can also revoke/revise that directive as it wants, and begin enforcing those federal laws regardless of state level legalization. Congress still has the power to pass actual laws that decriminalize it federally, but they’ve conveniently been spared from that politically charged topic by the Justice Department directive. Now they’ll be forced to address it. And with hundreds of millions of dollars in state tax revenue at stake, there will likely be more pressure to not white wash over it than their has been previously.