I don’t actually see it written anywhere that he is incontinent, as in he can’t control when he pees.

You might have thought this because the Guardian article says he must “wear diapers for adults with incontinence,” but that appears to be a descriptor of the diapers, not him.

In his GoFundMe he gets more specific:

I have a condition called Micropenis which causes me to be only 0.38 inches, which has made everyday tasks like using the restroom without making a mess is extremely difficult for me. Because of this, my doctor has advised that I must use pull ups unless I can pursue a medical procedure to help increase the size and improve my ability to urinate.

So it does sound like a physical issue getting the pee into the toilet, not general incontience.