He didn't said "a project for all possible language bindings", just
java bindings. Other languages' bindings would be separate projects.

Yes/no/sorta.

Java/JNA bindings can be used from Python, Ruby, Javascript, PHP as well as dialects of Haskell, Lisp, Smalltalk and a bunch of more obscure languages like Scala, Kotlin, Ceylon, etc.

It makes more sense to talk about bindings to particular runtimes these days, rather than particular languages.