Is this a serious question? Why would they subsidize people when there is no benifet to them? Subsidization means they are LOSING money when people use it. If the customers that are using 3rd party clients are unwilling to pay a price that is profitable for them, that is a very positive, not negative, thing for Anthropic to lose them.

The reason to subsidize is the exact reason you are worried about. Lock in, network effects, economies of scale, etc.