I can't speak for the others, but I was indicated for annual scopes from the start due to a finding of dysplasia at the time of colectomy. My scopes showed inflammation every year, but the real reason I was on chronic antibiotics was, and is, to manage the symptoms. Doctors normally don't medicate patients unless they have complaints. For 20 years or so, my GI described my inflammation as "simmering"- in other words, somewhat low grade. They were kept that way by a regimen of constant rotating antibiotics- cipro, flagyl, augmentin, xifaxin, etc. At some point it became worse than simmering (and also developed in the ileum above the pouch), and thats when I went on biologics (Remicade).
Not all people who have inflammation have bad symptoms. Low grade inflammation may not cause any at all. However over time and depending on diet, inflammation can and will worsen and symptoms will eventually manifest. Especially if it's not being meaningfully treated. Chronic antibiotics is a much better alternative than being in the situation C.S. is in because you do not want to go into a downward spiral and then be losing the J Pouch. Back in the 1990s I was having symptoms just like C.S. because I was not staying on antibiotics. Instead I was doing the 2 week course and then stopping which assumes everything is better after 2 weeks, when in many cases it’s not. This was proven on the scopes. In some cases pouchitis is very very resistant to treatment and J Pouches end up being reversed, but in many cases it's treatable and you can have a very good quality of life, as I have for 27 years. I am a full time attorney and never missed any significant amount of time from work despite chronic pouchitis and Crohn's for 25 years.
The other risk of nontreatment of inflammation is cancer in the retained rectal cuff. That's where it is most likely to develop because it is retained colonic tissue. Need I remind everyone that colon cancer is the #3 leading cause of death in the USA. That’s not a risk to be fooled with especially if you have chronic inflammation in the pouch and/or a dysplasia finding in your history. I check both of those cancer risk categories.