In late 2017, Disney and Fox announced a merger, a $52.4B deal where Disney acquired most of Fox's entertainment divisions. However, in order to comply with anti-monopoly law—Disney owns ESPN—the agreement stipulated that Disney had to sell off Fox's 22 regional sports networks, which includes the Yankees' gigantic network YES. (Fox acquired the formerly team-owned YES for $3.9B in 2014). While there's been plenty of speculation that the Yankees will try to buy a part of the network back, Amazon has thrown its hat into the ring as well.
While Amazon has dipped their toes into broadcast rights, partnering on a Thursday Night Football broadcast with the NFL, acquiring a rights deal with the Yankees would be a monumental announcement. Amazon has more cash than traditional cable providers, providers who will likely be competitors in any kind of auction. Over the weekend, The New York Times reported that the Yankees and Amazon planned to partner on a bid, a development that more or less ensures MLB approval.