Starting MySQL 8.3, GTID can contain tag and GTID can has a form <serverID>:<tag>:<TxID>.
See https://dev.mysql.com/doc/relnotes/mysql/8.3/en/news-8-3-0.html#mysqld-8-3-0-global-transaction-ids fot more details.
Binlog client currently doesn't support it and paring Tx ID would result into an error if the tags are used in GTIDs.