1) The leak was highly calculated and intentional. The information came out of the emails to & from Mark meadows that were obtained through the subpoena for the Dems Jan 6 investigation. It was released to the Dems stalwart Bob Woodward which is who they go to for these intentional stories such as they did for the Trump impeachment fiasco.
2) The Left KNOWS that it will not lead to anything itself (they have to). Clarence Thomas is no more responsible for the actions of his wife than Joe Biden is responsible for Hunter's actions as long as he is not linked directly to the action. In fact, Clarence Thomas and Samuel Alito declined to hear a challenge to the election and thus, no conflict of interest case even exists - and they KNOW this. Further, no laws were broken and Thomas' wife expressed the same concern as half the country - the Dems KNOW this also. They are also willing to toss aside their respct of women to have their own opinions seperate from their husbands to send the inference that Thomas' wife is simply an extension of him.
So WHY did they do this?
The answer is that the Dems via the MSM are again working to undermine the public perception of the legitimacy of the SCOTUS which is required in for an upcoming "Court Packing" effort.
The story also gives them the opportunity to further cast the Jan 6 protest into the light of a democracy threatening insurrection as if that is simply a matter of fact now - double bonus.
Further, note that SCOTUS nominee Brown was asked about her opinion of the court packing issue and she declined to comment (significant both for the fact that a politically connected Republican was concerned enough to ask about it as well as the nonresponse when she was more than glad to respond about the abortion issue and others).
The Dems don't have the votes for court packing now, but they are close, and they always play the long game. Expect a push for court packing in the near future.
It's important to remember that the leaks from the Dems to the MSM are always calculated.