From MySQL Documentation:
When gtid_mode=OFF_PERMISSIVE
then new transactions are anonymous while permitting replicated transactions to be either GTID or anonymous transactions. When gtid_mode=ON_PERMISSIVE
then new transactions use GTIDs while permitting replicated transactions to be either GTID or anonymous transactions
This mean that gtid_mode = ON PERMISSIVE
allows to have transactions with anonymous replication (traditional way) although new transactions are being made with GTID, that's why new version allows topology with GTID or anonymous replication.
This will help you with your request:
Fields that display a single GTID, such as CURRENT_TRANSACTION in the replication_applier_status_by_worker Performance Schema table, now display ANONYMOUS when GTID transactions are not being used.
Regards