Anticompetitive with themselves? It’s not like Claude / Anthropic have any kind of monopoly, and services companies are allowed to charge different rates for different kind of access to said service?

The anticompetitive move would be not running their software if ‘which codex’ evaluated to showing a binary and then not allow you to use it due to its presence. Companies are allowed to set pricing and not let you borrow the jet to fly to a not approved destination. This distortion is just wrong as a premise. They are being competitive by making a superior tool and their business model is “no one else sells Claude” and they are pretty right to do this IMO.