As the video has been taken down and no copies can be found from the internet, we cannot check those claims that it really contained some important information.
Note that the QGD was already played against Carlsen, before that leak.
Someone, who downloaded the vieo, converted it into the anygif. The essential part of the video is said to be in that anygif. This anygif is still present in the news. However, I do not see there anything important. There are only the names of the files, containing some moves. The analyses are not shown.
And it does not make sense to take the video down, if Carlsen's team already has it!
So I suppose that the journalists simply want something to write about. And it is an advertisement to the tournament, it throws attention.
We should not speculate too much about it.
Note that the QGD was already played against Carlsen, before that leak.
Someone, who downloaded the vieo, converted it into the anygif. The essential part of the video is said to be in that anygif. This anygif is still present in the news. However, I do not see there anything important. There are only the names of the files, containing some moves. The analyses are not shown.
And it does not make sense to take the video down, if Carlsen's team already has it!
So I suppose that the journalists simply want something to write about. And it is an advertisement to the tournament, it throws attention.
We should not speculate too much about it.