There are two reasons why I think closed systems will become more popular and survive the FDA regs.
And, there's one product that exemplifies both reasons - Phillip Morris' iQOS.
Even thought it's a vape product made for all the wrong reasons (i.e. it STILL HAS tobacco in it...), the sheer 800 pound gorilla behind it will make sure it gets approved. They are already in the process of getting it approved as a "Modified Risk Tobacco Product", and it's already on sale in Europe. People that want to quit but are not familiar with vaping are more likely to convert to that first. On top of that (from the Vaping 360 article), “Philip Morris has invested more than $3 billion in the research and development of ‘reduced risk’ alternatives to cigarettes.” PMI will make sure it gets approved and that it gets market share through convenience stores.
From a business perspective, closed-tank systems are much more profitable than open tank systems. That's because (as we all know) the real money is in the juice, not the hardware.
Sony Playstation loses money on every single PS4, but they make it up in the back end through the Playstation store. Same thing with Apple, Gillette shavers, etc...
I believe I heard that Phillip Morris has a program that pays $100 for people to convert to the iQOS in Europe.
When the regs crush the ability for small time manufacturers and juice makers to quickly enter the market, the closed tank system will be the most profitable option.