Claude Code 2.1.75 now no longer delineates between base Opus and 1M Opus: it's the same model. Oddly, I have Pro where the change supposedly only for Max+ but am still seeing this to be case.
EDIT: Don't think Pro has access to it, a typical prompt just hit the context limit.
The removal of extra pricing beyond 200k tokens may be Anthropic's salvo in the agent wars against GPT 5.4's 1M window and extra pricing for that.
No change for Pro, just checked it, the 1M context is still extra usage.
I have Max 20x and they're still separate on 2.1.75.