Hey Mauro,
putting them on the compile classpath deactivates compile avoidance, slowing down your builds. The warning describes what you can do if you didn’t intend to use annotation processors (use -proc:none). The list of processors is something I’ll add for 4.7. Gradle 5.0 will ignore processors on the compile classpath. If you didn’t use them, everything is fine. If you did use them, your project would stop to compile at that point.
Cheers,
Stefan