Notably, Disney couldn't buy Fox's core TV resources even if it wanted to. American companies aren't allowed to own two broadcast networks, and buying Fox Sports would raise antitrust questions when Disney already has ESPN under its belt.
Neither Disney nor Fox has commented on the apparent scoop, and it's crucial to note that there's no guarantee anything will happen. CNBC's tipsters said that discussions aren't happening at this moment -- the talks have been off-and-on. This doesn't rule out the possibility of the two companies returning to the negotiating table, but nor should you expect a deal in the very near future.
If something does materialize, it would have a tremendous effect on the media landscape, including streaming. While Fox would be more specialized, Disney would have even more reach than it does now. It would have yet another movie studio under its belt, more TV resources and a greater footprint abroad. And that, in turn, could bolster plans for its in-house streaming services. Disney would have a giant catalog of Fox shows and movies on top of ABC, Marvel and other heavyweight brands. It wouldn't have as much reason to play nicely with multi-studio streaming services like Amazon and Netflix.