CFD Trading in US – Portfolio Margin paving the way?

I never really understood why US residents cannot access CFDs. CFDs are just like any other derivatives, why someone can buy and write options which are arguably much more complex but not CFDs is puzzling. However, when I learnt that the conservative margin requirements for margin trading in the USĀ are regulated and resulted from the stock market crash in 1929. However, in recent times a new form of margining has been approved referred to as Portfolio Margining which allows clients to trade on margins that are significantly lower than 50% intital margin as is regularly required. This gives another reason why it does not make sense that CFD trading is not available to US residents.

Will this pave the way for CFD to take hold of US as well?