Iron Gate has said you'd need to start a new seed for big updates like Mistlands due to the biome additions, and then again recently for this launch to enjoy all the new features-was worded somewhere along those lines iirc

I know when killing a shaman or wolf they dropped their new items of barf berries and wolf's meat, so a copied seed works, just to what extent is what I'm curious about because I don't wanna miss out on anything

Thanks for a swift post, by old seed you mean the copied one, yeah?