To be fair, they might not have a source that is willing to go on the record or a second source for confirmation. If it's something as serious as the OS crashing, games not working properly or just an outright RROD-level of a fuck up, if they don't have confirmation or a source willing to go on record they probably can't report on it. Trust me, reporters hear shit off the record all the time. They know more than you do.
If they did report off the record stuff or reported without confirmation, blacklisting would be the least of their worries. MS would probably sue them for every penny they have. If it's such a serious issue that it could affect launch sales if it were revealed, you better believe MS probably wouldn't think twice about suing them.
Regardless of what you guys think of gaming journalists, they probably aren't making six figures. I doubt you want to risk going up against MS's legal team.