Sure, but your original question was about evolution getting rid of the genes necessary for a micropenis. That condition is very possible in our gene pool. Yes, there probably aren’t people who grow fins, even though that’s technically possible with enough specific mutations, so sure, evolution will eventually effectively get rid of traits in a species even if they’re not life threatening (though enough mutation for a human to grow fins would probably be deadly), but then your talking about evolution on the scale of millions of years.