User blog comment:B214/Question and Answers 3/@comment-3965848-20140620085601/@comment-16281343-20140620101640

They can use it but they don't.

Irina can still use Excalibur Mimic but does she use it? No, that's why it is listed as former in her page.

The same logic applies to the reversal magic for the Sitri group members.