I have had one cataract operation. I had dry eyes prior to this because of lasik surgery 5 years prior. I don't believe that cataract surgery "couldn't possibly cause dry eye." But, since I'm not a dr, my opinion isn't worth much. Keep searching, your doctor will never admit this "may" be the cause.
There may be a few others here with cataract surgery and hopefully they'll post, or those with knowledge you're seeking. Lucy
Don't trust any refractive surgeon with YOUR eyes.
The Dry Eye Queen