The downloadable zip file jboss-datagrid-7.0.0-maven-repository.zip contains only the JDG bits since 7.0.0, but other necessary bits are not longer included.
So it is necessary to add the correct EAP maven repository as well.

The README file for the jboss-datagrid-7.0.0-maven-repository.zip include a hint but neither the Migration Guide nor Developer Guide or the Release notes include any information about this.

This information should be added.

The missing parts are:
jboss-logging-3.3.0.final-redhat-1.jar
jboss-marshalling-parent-1.4.10.final-redhat-3.pom
jboss-marshalling-1.4.10.Final-redhat-1.jar
jboss-marshalling-1.4.10.Final-redhat-1.pom
oss-parent-9.0.0.redhat-2.pom
jboss-parent-19.0.0.redhat-1.pom
jboss-parent-19.0.0.redhat-2.pom
arquillian-bom-1.1.5.Final.pom
shrinkwrap-bom-1.2.2.pom
shrinkwrap-resolver-bom-2.1.0.pom
wildfly-core-parent-2.1.2.Final-redhat-1.pom