Sadly I don't think this is actually true. From that page:
DDL statements, atomic or otherwise, implicitly end any transaction that is active in the current session, as if you had done a COMMIT before executing the statement. This means that DDL statements cannot be performed within another transaction, within transaction control statements such as START TRANSACTION ... COMMIT, or combined with other statements within the same transaction.
Whereas with real transactional DDL, the DDL can be done within large transactions, multiple ALTER's could be rolled back, no changes are visible outside the transaction...
MySQL 8 was extremely new at the time this comment was posted. It's likely that mysql limitations were a big part of the thinking. The mention of pt-online-schema-change at the bottom makes me think so.
