Hi there, Congratulations!! Unfortunately, there doesn't seem to be a consensus among providers as to whether vaginal deliveries or c-sections should be recommended, so it will really depend on where you go. If you have a preference (especially if it's for vaginal), you can seek out a doctor/hospital that is onboard. Evidence either way is extremely limited, but I found a couple studies that were somewhat helpful when I made my decision (linked below).
I'm currently pregnant with my third, and I had my first two vaginally with no impact on my pouch! (I got my pouch in 2004 and have luckily only had pouchitis as a complication.) For me, since I knew that I wanted a few kids (3-4), avoiding a c-section was important because c-sections get riskier the more you have them. My OB even said that if I only wanted one child he might recommend a c-section, but since I don't, it would be better to at least see how labor goes and if we can manage a vaginal delivery. I met with a regular OB, high risk OB, and surgeon at the hospital I was delivering at (which was different from where I had my j-pouch surgeries since I don't live in the same area anymore), and everyone agreed that there was no clinical indication for a c-section. I was ultimately under the care of the normal (not high risk) OBs, and I'm planning to deliver with a hospital-based midwife practice this time around.
The biggest risk is that if you were to experience a third or fourth degree tear, the repair could be trickier because of your surgeries. BUT, there are several evidence-based strategies you can implement to reduce your risk of tearing that severely (I'll link that too). I worked with my doctor and doula to plan for 1) avoiding vacuum/forceps/episiotomy if at all possible, 2) if an episiotomy had been necessary, they would have cut it "mediolaterally" to direct the tear away from my anus, 3) my doula provided warm compresses that were applied to my perineum during pushing. I also looked for a hospital with a lower than average (about 30-something% nationally) rate of c-sections, and episiotomy rates as low as possible. If you are open to working with a doula, she could help you find the right fit for what you're looking for, as well as help you meet any labor/delivery goals that are important to you.
So I think it comes down to what your priorities are and what you're comfortable with. There are lots of j-pouchers who have gone the c-section route and been happy with their results. Just know that you have options, and if you don't like what you're hearing from one provider, don't be afraid to switch!
Happy to answer any questions, and good luck!
https://link.springer.com/arti...%2Fs10350-004-0569-0
https://link.springer.com/arti...%2Fs10350-004-6411-x
https://link.springer.com/arti...07/s10350-005-0124-7