OpenAI may not be training GPT-5, but Sam didn't say anything about GPT-4.5.
And actually there is no law or anything that says that any particular change or improvement to the model or even new training run that necessities them calling it version 5. It's not like there is a Version Release Police that evaluates all of the version numbers and puts people in jail if they don't adhere to some specific consistent scheme.
source?
> "it’s easy to create a continuum of incrementally-better AIs (such as by deploying subsequent checkpoints of a given training run), which presents a safety opportunity very unlike our historical approach of infrequent major model upgrades."