If a node closest to diverticulum was negative then I understand why others were not removed. That reduces your chances of metastatic disease. Unfortunately the urine contained cancer cells so the bladder and urethra were exposed and microscopic lesions there can show up at a later date. That continued eruption of new "areas to watch" or actual papillary or erosive tumors is what made my husband choose radical cystectomy. I know many people live for years with constant monitoring of the bladder by cystoscopy and subsequent TURBT procedures to contain these new growths. The more aggressive the original tumor, the more likely to see rapid recurrence. Regular monitoring via cystoscopy seems like a good choice. My husband also has abdominal CTs to watch for metastatic disease per his Mayo team.