It's definitely not normal or acceptable. The long block replacement took care of the mechanical failure (assuming they also flushed or replaced the oil cooler, oil pan, and lines), but they obviously never diagnosed and addressed the driveability problem. There are other parts and systems that didn't get replaced when they did the long block, and since the problem became evident before the engine failure and long block replacement, it's pretty obvious the problem is with one of those other parts and systems. One part that immediately comes to mind is the throttle body for instance, along with the associated sensors. Since a vacuum leak would cause a situation like what you described, I suggest you first check to make sure the rubber plug on the throttle body vacuum tube is still installed and secure. Many have had them come off. Other issues have been reported with the throttle plate, the throttle control stepper motor, sensors, etc.
If this shop isn't capable of handling basic diagnostics, and it sounds like they aren't, you may need to find a better shop.
Jerry