For as long as I can remember, Google News publishers needed to have 3 digits in their URLs in order to be included in the Google News Index. There was an exception to the rule, but overall to be indexed and accepted into the Google News index, you need your URL structure to have 3 digits.
That is no longer the case!
Google's Stacie Chan said in the Google News Help forums that they are doing away with the rule. Stacie wrote:
We’re happy to announce that Google News no longer requires you to follow the “3-digit rule,” which previously required you publishers to have a unique number of 3 digits in your article URLs. This means more news content indexed in Google News, however you structure your URLs.
Your URLs still need to be unique and permanent but you do not need the arbitrary 3 digits in the URL anymore.
Why did Google finally remove this requirement? Stacie wrote:
Over the years, your article URLs have evolved and not all news content had a set of unique three digits. Our team took this into consideration, and decided to remove this rule in order to include more of your great news content. And we believe more of your great content means more happy readers.
Forum discussion at Google News Help.