I just went to a random OpenAI blog post ("The new ChatGPT Images is here"), right-click saved one of the images (the one from "Text rendering" section), and pasted it to your [1] link - no metadata.

I know the metadata is probably easy to strip, maybe even accidentally, but their own promotional content not having it doesn't inspire confidence.

Yeah that's been my experience as well. I think most uploads strip the metadata unfortunately