Imho this was not one of those kickstarter exclusive heavy campaigns.
This is the only stuff not in retail and I don't see the exclusive word being used, so no need to worry this will probably become available.
There are plans to have some stretch goals be not included in the retail copies of the game. Those stretch goals would still be available through us at conventions and possibly through Board Game Geek at a later time.
Imho they did it right in this campaign.