Summary
Admin unsubscribe HTML is overriding unsubscribe language hard-coded into an email template
Issue
You are trying to add unique unsubscribe text to a specific email asset template's code (for example: unsubscribe text in another language), but the Admin Unsubscribe HTML found in Admin > Email > Settings is overriding it.
Environment
Design Studio/Admin
Solution
To implement dynamic unsubscribe text by language into an email asset, we recommend using the Segmentations and snippets, placing the {{system.unsubscribeLink}} directly into the email asset via the snippet as the presence of this system token in the email asset should override the Admin unsubscribe HTML.
Make Your Unsubscribe Message Dynamic for Languages | Adobe Marketo Engage