the preferred pronunciation of the planet's name is with the accent on the first syllable

Didn't used to be. It changed overnight when the astronomers discovered a ring around it. Seriously. I was there. I heard it with my own ears. The thought of Walter Cronkite saying "Ring around Uranus" was just too much and some proactive censor caught it, no doubt. Ring around the collar was well known in advertising circles at the time.