What Happens:

When creating a new world, an installed addon BP's "structures" folder doesn't transfer to the copy of that Behavior Pack which is saved with the world in the "minecraftWorlds" folder.

Placing the same Behavior Pack in the "development_behavior_packs" folder produces a different result, due to the fact that the "structures" folder is read directly from the development folder and not from the world folder.

So if a user deletes the addon pack from Minecraft, the world that was created has an incomplete copy of the BP that was added, and no structures can be loaded. Additionally, if another user joins the world and doesn't have the addon installed on their device, the addon they receive is incomplete and doesn't contain the "structures" folder.

What I Expect to Happen:

When an addon is associated to a world, the entire addon should be transferred to the world folder to ensure it functions as intended for users joining via network and in instances where the original BP is uninstalled from Minecraft and the world is subsequently loaded.

I have included a screenshot of a behavior pack and how it is installed into the "com.mojang\behavior_packs\<PackName>" folder alongside the same behavior pack and how it saves within the "com.mojang\minecraftWorlds\<world>\behavior_packs\<PackName>" folder (that addons are copied to to allow them to properly function when other players join).