Yes, all items included in the Founder's Pack will remain exclusive to those who purchase them during the Early Access period. These items, like cosmetics, emotes, and other special rewards, are our way of thanking our early supporters, and they’ll stay with your account for the life of the game.
The "Founder's Exclusive" items, such as the Longship Cosmetic Set and Valhalla Iska Umbra Skin, will not be available again after Early Access ends. While we’re on Steam, you’ll be able to purchase the Founder’s Packs, but once Early Access ends, those exclusive items won’t be available anymore.
The Monthly Founder Bonus and Monthly Premium Founder Bonus, which provide rewards during Early Access, could show up again in the future.