They let anyone create and use one after all.
The only reason approval exists at all is so users aren't tricked into running low quality or spammy plugins.
You could consider this similar to someone revealing that lots of apps banned from app stores are available on other websites and one could write the headline "banned app leaks onto apkmirror.com, is google security compromised?"
Really? Allowing the suppliers of plugins to verify that ChatGPT understands the descriptions and uses them as expected (especially for ones which perform actions beyond data retrieval) before releasing them into the wild as intermediaries between users and the systems exposed by them isn’t part of that?
As an external observer, all I can say is controlling access to plug-ins via client side validation was an unusual choice and it makes me worried they made the same unusual choice elsewhere to protect data I care about.
The thing that's affected here is the responses you alone see.