Why is it impossible to create a bundle that contains unreleased add-ons?

For my game, I have created 3 add-ons (skin packs) that have been approved by Meta. I'd like to offer these 3 add-ons in a bundle at a lower price point, however I am unable to add unreleased add-ons to the bundle.

I dont want there to be a period of time in which 3 of my add-ons are publicly available for purchase without a corresponding bundle containing the 3 add-ons also being available at the same time. Why is it impossible to create a bundle with add-ons that are not yet released? Players of my game are going to end up leaving negative reviews saying they bought one of the add-ons, only for us to release a bundle with a better deal 2 weeks later!