Somehow I think this one is not Sony's fault entirely.

Time Warner has recently moved towards "unifying all their streaming platforms" which meant that a lot of adjacent services will close/migrate to Discovery+ directly.

I am someone that suffers the fallout of them shutting GCN+ down, which gives me about two weeks to watch around 100 cycling documentaries that the GCN people have put out in the past 3-4 years. Granted I haven't paid for them individually, so it's not as painful as for the Sony customers, but they will be shutting down access to all of them without any backup plan and without a look back.

The people at GCN seem to be as baffled as everyone else about this move. Luckily they still have a good presence on their Youtube channel where they have more accessible content.