Now that they've been handed a majority they'll find some other feckless reason to not oppose it.
In fact, I'd hazard a guess that the GOPe leadership views their majority in both houses as a liability and an inconvenience; it makes them have to go make other excuses for doing nothing about anything.
As I said, the GOP may have dropped the ball intentionally - or they may simply have been too stupid and intimidated to pick it up when it was handed to them. But I think Roberts did give them a way of overturning the whole law, and for some reason, they just chose not to do so.