I wonder if first-party offerings like Codex and Claude will follow suit. Most "agents" are utter nonsense, but they cooked with the CLI tools. It'd be a shame to let go of them.

Eventually that is the plan. Like we saw with Claude Code, they want developers to get a taste of that unlimited and unrestrained power of a state of the art model like Opus 4, then slowly limit usage until you fully transition to metered billing and deprecate subscription based billing.