Could eating less solids after wisdom teeth extraction cause more frequent urination?

Yes : You are probably eating more soups and gravy-type foods since the extraction. In addition, if you were put to sleep, you may have been given IV fluids to keep you hydrated which will make you urinate more often. Continue drinking clear fluids as this will speed up your healing.

Sure: If you are eating less solids, and drinking more and are not as active, then you would expect to urinate more frequently. This is all good ! keep up the high fluid intake -- it helps healing.