It could be useful in a dynamic situation. You could launch it into an area you know the enemy are in. As they approach, you can use other methods to get exact locations (e.g. spotters, or a flyover). An update can be sent out for an exact target to hit, based on where it is now, not where it was at launch time.

You don’t need to know exactly where the drone is with this, so long as it does internally. A dead reckoning estimate is good enough.