The "Create New Outfit" button on that page should do that, and I think it's working as intended. If you would like to give feedback on this button please do so in Site Feedback, we will absolutely take your feedback into account! This topic is about not being able to change saved avatar names. Let's stay on topic and make one forum topic per issue as per guidelines in this forum.

Fixed- you should be able to rename outfits successfully again :)