Not necessarily. If your wife doesn’t reinjure herself during these early weeks, she may actually get some nice healing at the injury site. The shoulder may not be able to heal itself completely and surgery may still be the best option.
During the waiting time ask your doctor about some simple exercises to keep the shoulder joint mobile. Codman’s, or pendulum, exercises can be done three to four times per day followed by ice.
Let pain be your guide. Movements that cause severe pain should be avoided. Your wife should be aware of her breathing and avoid holding her breath when moving the shoulder. Breathing and relaxation while moving through the pendulum exercises can help prevent unnecessary scar tissue from forming while waiting for the MRI.