"Wales said entries have to meet a standard of newsworthiness and, as a general rule, should not be written by an interested party - either a supporter or an opponent."
I'm guessing he was talking about biographical articles, for which that does sound like a pretty good general rule. It's already an informal rule that the subjects of biographies have to be super careful if they ever try to edit their own articles, and I'm pretty sure we were already discouraging it outright.
And on the other hand, given that Jimbo's been devoting a lot of attention to excessively derogatory biographical articles lately, I can see the point that editors with a strong negative bias are potentially an even bigger problem there than in other contentious articles. And of course biographies about politicians -- which I now see is what the MSNBC article was about -- have their own special degrees of contention.