I read a pretty good article a couple of months ago that pointed out that the computer infrastructure needed to implement this mess was not ready and would take some time to get ready and work. Not only not enough computing power absent but they don’t even have all of the software written and in place to make this thing work right.
I think the fact is that they haven't finalized the rules, and so one might make the claim that they haven't even started some parts of the software.
Complex software takes time to design, develop, test and deploy. I believe that -- in part -- they are at the "design" phase, and the government shutdown is probably going to slow their efforts.