From recent ChatGPT (GPT5.6) conversations where I've seen occasional reasoning leaks into the UI, it's clear that something like this is already implemented, and I'd speculate that this is the majority of recent claims of less token usage. Not sure if they are literally prompting for cablese of course.
"Need check output vs prev. Ran script, results fine, need prep next step. Ready? Go."
"Need check output vs prev. Ran script, results fine, need prep next step. Ready? Go."