Problem with custom token
A token like [field_display_name] in the rewrite results option for the display of a Views field is not the same as a token everywhere else in Drupal, so hook_token_info() and hook_tokens() won't help you.  On behalf of Drupal, Views, and the million or so other available words in the English language, i apologize.

Instead you need to extend a Views field handler class and override the document_self_tokens() and add_self_tokens() methods.  You can instruct a field to use your custom field handler via hook_views_data_alter() (thanks to Daniel Wehner for this info, and very likely the hook itself).

You can see example code from my need for adding a Views field replacement pattern / token.

If you need help adapting it for your need above let me know and i'll write that here, but the remember to list in your .info the file with your field handler extending class so that Drupal registers it, and it'll work fine.