This is a topic that can often lead to some strong opinions online, especially on forums like this which are aimed more toward healthy support of individuals rather than encouraging extreme desires. There are many here who would urge that trying to become incontinent is unhealthy and should be avoided, there is a lot more to being incontinent than most ABDL folk realise, it may be fun to dream about but can make real life extremely difficult, expensive, and destructive. Great care, consideration and research should be done before anyone thinks to try.
My personal opinion is that as long as they have done due diligence and fully considered what it would mean for them and how it would impact their lives it is still a personal choice and if someone truly desires it then let them try. I would strongly advise anyone to not just think twice but many many times before making that choice as it would be life changing and may be even harder to regain control if you wanted to stop. Also to experiment under controlled conditions first. (i.e. try wearing 24/7 for 2-3 months, try to maintain your awareness and hold it in but take no breaks from wearing so as to see how it would affect you if you had to wear full time.)
With that said to answer your specific question of whether wearing long term can lead to incontinence.
I believe it certainly can lead to at least mild incontinence however from things I have read and accounts of those attempting to become fully incontinent it would seem that it takes (for most) a long time and some very concerted effort before any level of incontinence is reached.
If you have been potty trained well and have no prior issues with continence then you will have many many years of "programming" and practice to overcome, simply wearing nappies all the time should not in itself lead to incontinence as long as you are still maintaining some awareness of when you need to go and making attempts to hold it in. but even allowing yourself to go at the slightest urge and trying not to notice it will take much time for your body to become accustomed to just going without alerting you.
Certainly though by wearing 24/7 and just releasing everything as it comes will cause the bladder capacity to decrease and reduce the amount and the time that you are able to hold in leading to more regular toileting urges. Anytime you choose not to go though and hold it until later would set back any "potty un-training" that you might attempt this means that if un-training is something a person desires they would have to let go wherever and whenever even if not wearing a nappy.
The problem is that while many people into ABDL love the idea of being able to go like a baby and just use a nappy with no ability to stop or even notice when they go the inconvenience of needing to wear 24/7, always carrying spares, changing in public places, family, friends and co-workers finding out, cost, disposal, storage etc. is incredibly high, just ask around in the IC forum for what life is like when you have no control and you will find many people with stories that will put you off the idea.
Even ignoring all the effects it would have on your daily life most of us non-IC ABDL's wear for pleasure or comfort or stress relief etc. and when wearing becomes a need not a choice it can quickly lose the appeal and become a chore and if this happens after you have managed to make yourself incontinent you may have a much harder time going back.
I'm was just stating the joys that come with wearing 24/7 it's really not worth the faff. As for BPH I don't have that but it can lead to issues of retention which can require medication (been on those and hated them) or intermittent self catherisation if you need any help with these in the future feel free to ask.