I think part of the confusion is that we are assigning an attribute to an API that can and should be willfully ignorant of the ecosystem around it. The APIs are not open core but the companies around them are using an open core business model.

antirez as the creator of redis is stating that redis is not open core. antirez as an employee of Redis Labs is working for a company that has adopted an open core strategy, and which is using redis as their core, which doesn't make redis the API open core.