Some of the legacy formats in the game (Like Generation GX, Arc-V, Zexal, etc) don’t have a date in their name to filter them out manually in the deck editor. Ideally, upon selecting the limited list, these cards that did not exist yet wouldn’t show up in the first place.
Also, when making a goat format room, the game already filters out cards that were released after 2005-08-17. However, this date is different than the one displayed on the limited list being “Goat 1.4.2005”. I believe this to be an oversight.
EDIT: changed the title cuz i accidentally wrote down deck instead of date in the title after goat format