Yes, it is actually interesting that all mammals take the same amount of time to urinate. That means that both humans and a large percentage of animals urinate for the same duration. In my opinion, this brings us humans and animals closer together, which could even be another piece of evidence to prove evolution.
It is very interesting and speaks a lot for our different biology. Elephants can urinate 20 gallons in the 20 seconds that everything else takes to urinate any other amount. Our size differences, especially in our bladders and urethras/privates, all play a factor. This can even be beneficial information: if people can figure out how the animal that pees the most in the shortest amount of time does what they do, then our construction of pumps and the like may come to grow to be more efficient as we emulate those bodily systems at work. Most everything takes 20 seconds to pee, regardless of how much pee there is, so it's a matter of finding which animal pees the most.
Species have evolved in so many different ways, it is definitely interesting that all mammals take the same amount of time to urinate. If their bladders are bigger, such as with horses, evolution gave them the ability to urinate with more force. Smaller animals have a slower urination stream to keep it at the same time. Any time we all have something in common it is interesting.
I can't think of many things that are less interesting to discuss than the amount of time that mammals take to urinate. In fact, I can't believe that it is even a subject of research or investigation. Don't people have better things to worry about? At the end of the day, who cares?