CT scan standard for Papillary urothelial bladder cancer, high grade?

I believe it is standard care. I'm under treatment with Mayo and have had CT Urograms every threee to six months in the beginning and now once a year. I'm in a different situation from you; I've had my bladder removed and replaced with a neobladder but they still do the scans. If I recall; they will continue this for another year or two just to make sure nothing has returned. Good luck with your treatment.

How did the neobladder surgery go and life with it since?

The surgery went very well; my surgeon was Dr. Mark Tyson and his team at the Mayo Phoenix clinic in March 2022. Dr. Tyson is a pioneer in robotic neobladder surgery (two tiny incisions and no scar on my belly). He and his team at Mayo are fantastic. The surgey took about 5-6 hours and I was 5 days in hospital post-surgery. Worst part was the catheter; once that was removed I felt fine. First few months I needed to wear adult diapers (Depends) all the time and went through 2-3 a day. After that I was able to go without any during the day and only wear them at night now. I look perfectly normal and can go about my day as if nothing has changed. Only occasional incontency (much less of an issue than a menstral period). I swim, jog, exercise, hike and do all of the activities I did before. I am very happy with the result and would recommend a neobladder to anyone.
I am happy to share my experience with you if you go down this road and have any questions at all.

Can you tell me about your experience for your neo bladder

Everyone is different but I think my experience is fairly common. I was 72 at the time of the surgery with no major health issues except the bladder cancer. The details of the surgery are in my original post; no need to go over those again.
Now for the gory details. Immediately post surgery you are incontinent and must wear adult diapers. With your original bladder your body has all sorts of nerves that tell you when you need to urinate and muscles that keep the urethra closed until you want to urinate and muscles to expel the urine. But that is gone when they remove the bladder and you have to get used to other signals that your body gives to tell you it's time to relieve yourself. You also have to strengthen the muscles that control the flow of urine (Kegal exercizes) and learn to use your abdominal muscles to push the urine out (a bladder is enclosed in a muscle to expel the urine, the intestine is not). Everyone is different but you will learn to sense these new "signals" and control the flow. For the first couple of months, I was in adult diapers all the time (I went through about 3-4 diapers per day) but soon I was able to go without during the day; still some leakage but not the end of the world. I only wear depends at night now. Also, you tend to go to the bathroom more often than before (at least I do) and so I'm up 2 or 3 times at night. Best to limit fluid intake after 6PM. Also, because you are using a portion of your small intestine for the neobladder, your urine changes. The intestine produces mucus and continues to do so in your neobladder. So your urine is more viscus and I guess for some patients this mucus can be a bit heavy and may result in issues with the urethra so you need to drink plenty of fluids and urinate when you have to urinate.
The other issue is; for men, they remove the prostrate at the time they remove the bladder because the two organs are so interconnected. This means severe ED that Viagra doesn't help (at least in my case). This is a big change and something you need to get your head around. Everyone is different but you need to be aware that this is going to happen.
After surgery, you start a regimen of visits and procedures. At first every 3 months, then 6, then annually where they do blood work, urinalysis, chest imaging and a CT urogram where they image your bladder. This is followed by a consult with the resident who assisted the surgery and then you go home; about a half a day's visit. I'm not sure how long these annual visits will continue.
With the exceptions outlined above, my life is pretty much back to normal. It's a new normal but there are no physical activities I can't resume, no trips I can't take (trains, planes and cars), no foods or drinks I can't consume. If you must have your bladder removed, a neobladder is the only thing I'd recommend. Let me know if there is anything specific you want to know. I'm happy to share.

@mgb007, I want to make sure you saw @steenrl's thorough and helpful reply here. https://connect.mayoclinic.org/comment/1109371/