Do you believe the court would vote 7-2 to lift the injunction, if the intent was not to overturn it completely?
No, not necessarily. And in fact the 7-2 decision suggests they haven't made up their minds. If that ruling suggests what they'll eventually decide, it would probably have been a 5-4 vote.
Constitutional law is very complicated. I believe they voted as they did because they believed the president DOES have the right to impose such a ban on an "emergency" basis. But his right isn't entirely unfettered, and that's what they'll decide when they consider the merits (or lack thereof) of the case.