This is a fairly large assumption, that the secret was important to them. Sometimes a curtain in front of the stage is all that’s needed, until things are ready.
One would reasonably consider that the secret should be important to them, given their express concern over safety considerations in particular.
The plugin system is completely open. It's a manifest file like a robot.txt.
You can hook up the API to those endpoints yourself with minimal technical skill.
Many people had already integrated Wolfram and that was before there was an open format specifically designed to be easily integrated into ChatGPT.
At the end of the day for how overused the term "FUD" is on this site, this is the first time I've actually seen it in action.
Leaving aside OpenAI’s intention, its an indication of OpenAI’s failure to restrict access via their system to something to which they have represented to plugin suppliers that their system will restricted access to only a small, supplier-identified group of testers.