Best is to replace the implant promptly. If not, the pocket will begin to shrink, and what would be a simple procedure as in back to work the next day, will become more complex, requiring addition manipulation of the pocket, and more chance of less than good symmetry.
Other than that, there is no harm in delaying for most people. However, if the deflated implant has firm folds, the implant may be uncomfortable, and may injure the breast skin if you lie on the implants.
All the best.