I think a bigger question is whether reputable sources --those people trust for whatever reason, would use this technology to prop up ideas and or to create narratives.
I don't think it's far-fetched. We've already seen where videos are misattributed[1] to stoke fear or to promote narratives --by widely trusted news sources.
[1] This was foreshadowed with "Wag the Dog" but happens often enough in the media today that I don't think use of "deepfake" technology is beyond the pale for any of them.
It almost doesn't matter now that people have fractured on which sources they consider reputable. Trump called a CNN reporter "fake news" and presumably his followers think of them the same way I think of Fox. I absolutely think that Fox would use technology to lie, and I'm sure Fox fans think that "the liberal media" would. So people are going to think that reporting is fake whether or not it is
According to an article you found online. That's exactly my point, if we can't trust news sources then we can't really know anything. Because of my aforementioned distrust of Fox News, if it were written by them I'd dismiss that article out of hand placing no truth value on it either way. I'd expect somebody that distrusts CNN to do the same if it were written by them.
"It's confirmed!", "They admitted it!", and other unprovable internet turns of phrase in comments sections are really just "I believe it because somebody I trust said so" and that only has weight as long as trust has weight.
If the accused admit to something it's more believable than the alternative (that they were forced into false admission).
So in this case if the Ukrainian government admit to making things up then I would think it's believable that they made something up for the sake of propaganda. We can also check more independent sources --read Japanese news, or Indian news sources, etc.
We don't know that the accused admitted to anything. We know that the Washington Post says that they did. The world becomes very solipsistic when you lose trust in reporting.
I don't think it's far-fetched. We've already seen where videos are misattributed[1] to stoke fear or to promote narratives --by widely trusted news sources.
[1] This was foreshadowed with "Wag the Dog" but happens often enough in the media today that I don't think use of "deepfake" technology is beyond the pale for any of them.