This feature is backward compatible. To make the terminology used clear throughout the documentation:
Old permissions refer to the R4J permissions outside of Jira project permission schemes which are located in R4J project administration page.
New permissions refer to the R4J permissions integrated to the Jira project permission scheme.
Projects that have set restrictions using old permissions before this version will continue to use those permissions, unless the administrators manually choose to use the new permissions.
Projects that do not use the old permissions, including newly created and activated projects, will automatically only be able to use the new permissions.