But very few TIMs have genital surgery. Most, like the guy in the OP, still have all their original plumbing intact.
Moreover, during the process of male arousal and emission that ends in ejaculation and orgasm, the male urinary tract closes off where it exits the bladder - which is way upstream of the urethral opening at the tip of the penis where urine would leak out. Also, as it exits the bladder, the male urethra goes through the prostate gland - and is fed into by the male ejaculatory ducts leading to the seminal vesicles via the vas deferens. The prostate and seminal vesicles are the glands that make the precum that clears out the male urinary tract and the seminal fluid whose purpose is to transport sperm from the testes through the male urethra and out the tip of the penis.
This makes the male urethra anatomically and functionally very, very different to the female urethra. Due to the very common problem of prostate enlargement, which every guy after 50 has to deal with, the urinary tract issue that males struggle with is inability to empty the bladder and urinary retention - which is a problem opposite to the sort of leakage that females commonly experience.
Even when TIMs have genital surgeries that remove their balls, invert their penises, shorten their urethras and relocate the urethral opening to the fauxlva, they still keep their prostates, ejaculatory ducts, seminal vesicles and vas deferens all in place. And their bladders too. This makes TIMs develop the same exact problems with urinary retention that all guys go through due to prostate enlargement. Plus, it suggests to me that whilst they no longer make sperm, they most likely still make all the other elements of seminal fluid in their prostates and associated organs when they are sexually aroused. If that's the case, then in TIMs who have had genital surgery, the spermless seminal fluid would come out of the end of their shortened urethras in exactly the same way that semen came out the tip of their penises prior to surgery. Because there's no other place for said fluid to go.
I am sure that many TIMs who get genital surgeries end up with messed up urinary tracts and with urinary issues as a result. Some no doubt have incontinence. But because their urinary anatomy remains so completely different to female anatomy, the post-surgery problems they develop won't be analogous to the urinary incontinence problems females experience. Females and males both have bladders and urethras, but only the male urethra is threaded through the prostate gland and connected to additional ducts and glands whose purpose is to make seminal fluid.
Yeah but doesn't that only apply to women?