Gradle Plugin Repositories and Maven Central

Coming off https://discuss.gradle.org/t/confusion-over-plugin-dependencies/21212/10, I’ve been exploring trying to get gradle plugins into our corporate Nexus, which is supposed to be (but isn’t) a faithful mirror of Maven Central. I went to the https://search.maven.org/ which describes itself as

The Search Engine for The Central Repository

(Is that true, btw)?

Anyway on that site I found that some but not all of the gradle plugins I use are in Maven Central.

So I have this situation, apparently

Maven Central has some but not all of the plugins in the Gradle Plugins site and my Corporate Mirror mirrors some but not all of these plugins.

Frustrating.

My question for this forum is: what, if anything, is the policy regarding the Gradle Plugins site and Maven Central? Shouldn’t everything in the former also be in the latter?