It’s a little quality of life improvement: for the purpose of crafting - I have building pieces on my mind, primarily - consider current follower’s inventory an extension of the character’s own, so, say, wood and stone would be pulled from pet/thrall seamlessly when crafting a building block. It makes sense conceptually (in that case follower is the ‘carrier’ following the player around and hauling the supplies) and would’ve made building process a little nicer.
Now, I may not be noticing any ways in which such a change can be abused for something, so if someone can see issues with it, feel free to share.