The Senate has been using “replacement in the nature of a substitute” since Henry Clay.
That makes this a mighty weak (though not impossible) argument...
There are many cases pending that will allow a strong ruling, either for or against. The process takes time.
To issue a stay on the grounds put forward would merely add to the confusion. Given all the one year waivers, most of the people are not subject to the law yet anyway.
In my mind, the strongest case is by the states who have elected to not have state exchanges and the precise wording was simply ignored. I can not see how the explicit wishes of the Congress plainly stated can be ignored.
That is the shoal rock that will wreck the ship of Obamacare.