The module-info.java of java.base exports jdk.internal.javac to:

        jdk.incubator.vector, // participates in preview features
        jdk.jartool, // participates in preview features
        jdk.jdeps, // participates in preview features
        jdk.jfr, // participates in preview features
        jdk.jlink, // participates in preview features
        jdk.jshell; // participates in preview features

because they used to participate in the ClassFile API which was a preview feature some releases back. ClassFile API was finalized and delivered in Java 24 through JDK-8334712. So these exports can be removed.