Chances are the damage to your ipad isn't the drive. It's the mother board or power supply that's been shorted out. I'm basing this on me having washed a few flash drives in my lifetime, and once they dry out the data is still there and perfectly fine.
Theoretically, sure, they could restore it. The question comes down to, as others have said, do they want to? Are they going to part out your machine? If so, then someone else's ipad could end up with your flash drive in it....but their interest really isn't going to be your data. It'll be them wiping things so they can sell the part as 'functional but used'.
Your data is as safe as the integrity of the tech parting out your machine.