Only one (the second) of those links shows JavaDoc.
The first shows DSL docs.
The last shows Kotlin DSL docs.
Indeed for that class they seem to be very similar, or maybe some things are just included from the other to have an overall document with uniform style instead of linking from one to the other. 🤷♂️
But at least between DSL docs and JavaDoc you often have significant differences, which probably also is the cause why the former links to the latter.