Sure others won't pay $1.5 billion, but they won't get exclusivity so they wouldn't have to pay that much. No one else could even USE exclusivity, except for Dish. Cable companies can't, because none of them have near the reach satellite does, so it is worth less to them (and to the NFL, who would potentially lose some of its most hardcore fans who might disengage if they no longer had a way to follow their favorite team) Same reasons on both sides for streaming.
So selling to a streaming provider could ONLY be on a non-exclusive basis, and that would open up the bidding to others who could get it on a similar non-exclusive basis. Maybe Comcast would decide to get it, to offer to its customers as a way to steal the ones who currently get Directv only because they offer NFLST - these are valuable customers because sports fans are the least likely to cord cut. Maybe Dish would get it, hoping to steal some commercial customers from Directv, especially on the west coast where they have Pac 12 Network and Directv doesn't.
Regardless of who else got it, Directv would want it to try to keep their commercial customers - who wouldn't have a streaming option (none of the streamers license commercially, that isn't something they could set up overnight even if bandwidth wasn't a concern in many cases) and going with cable is a poor option because you have to rent a receiver for each TV. Plus keeping NFLST would mean likely keeping a decent chunk of their residential NFLST customers, some of whom might not have the option to stream/switch because of where they live, and others who would stay with Directv out of inertia.
So selling to a streaming provider could ONLY be on a non-exclusive basis, and that would open up the bidding to others who could get it on a similar non-exclusive basis. Maybe Comcast would decide to get it, to offer to its customers as a way to steal the ones who currently get Directv only because they offer NFLST - these are valuable customers because sports fans are the least likely to cord cut. Maybe Dish would get it, hoping to steal some commercial customers from Directv, especially on the west coast where they have Pac 12 Network and Directv doesn't.
Regardless of who else got it, Directv would want it to try to keep their commercial customers - who wouldn't have a streaming option (none of the streamers license commercially, that isn't something they could set up overnight even if bandwidth wasn't a concern in many cases) and going with cable is a poor option because you have to rent a receiver for each TV. Plus keeping NFLST would mean likely keeping a decent chunk of their residential NFLST customers, some of whom might not have the option to stream/switch because of where they live, and others who would stay with Directv out of inertia.