The difference is that the 21CF acquisition wasn't a fire sale. If anything they significantly overpaid for the whole only to have Disney give the various parts away later.It began with the Fox acquisition. Big chunks of cable infrastructure were sold off or decommissioned for Disney and Comcast and Sky (mostly in Europe). If the new shiny things weren't applicable to streaming, it was trashed.
This is interesting because Comcast is lumping in well known assets (CNBC, USA, MSNBC, etc.) in. Yes they may be loosing money, like most of linear, but these are first tier properties, some of which are very tightly integrated into the flagship NBC.
Now that Comcast moved first with this, does Disney copy them? My gut is that this gives Iger the cover and framework to jettison ABC and related money loosing linear TV properties. But it seems like the whole mad rush to ditch linear TV is like throwing the baby out with the bathwater, especially considering the people pushing it are the same that never thought the streaming bubble popping could occur.