The problem with this is that, much like fake news, no refutation or retraction ever spreads as wildly and virally as the original sensational claim. So people

The problem with this is that, much like fake news, no refutation or retraction ever spreads as wildly and virally as the original sensational claim. So people will carry on believing that Russia hacked the power grid, just like they have with all the other bogus, sensationalised, narrative-pushing claims so far. It's basically a way for papers to have their cake and eat it: they get to profit from the original bogus claim while insisting that it shouldn't affect their reputation for good journalism because they corrected it.