Well,I agree with that, but of course the part in brackets does become relevant if the person in question is still being sought.
Does it become useful in a news report though?
"A white man is being sought"
There's a white man! It could be him! He matches the description! He's a man, and he's white!
or
"White men are criminals. There were dozens of them mentioned on the news"
Whichever way you look at it, if they are still seeking the perpetrator, then mentioning the colour / ethnicity still narrows it down - even if it's 50/50?
So, perhaps it remains relevant.