I refuse to praise Oracle for anything. But I could make an exception if they put Isolates in the CE version of Graal and not only the Enterprise one. :)

Also, obviously Oracle didn't do this out of the kindness of their hearts, if they didn't contribute Graal into the OpenJDK the would risk to Graal never become anything other than a niche VM because most people, specially big clients don't want to change VMs and the CE version will be their new gateway drug to their Enterprise version of Graal.