I've really enjoyed For All Mankind, but looking on twitter there's almost no fan base talking about it. Contrast with Ronald D. Moore's previous sci fi hit: the 2000s reboot of Battlestar Galactica. There were free to watch webisodes, a lot was done to encourage and enable a fan community.
It does feel like Apple are so obsessed with the IP that they're missing that having fans and the constellation of content that people will just go off and make because they're excited about a show is crucial to their success.