The tall cans have more surface area. It does mean slightly more materials (but not that much because the can thickness is not uniform), but also more visibility in vending machines and stores. It’s a purely marketing decision.

The runner is open source, and that’s what matter in this discussion. If you host the model on your own servers, you can ensure that no corporation (american or Chinese) has access to your data. Access to the training code and data is irrelevant here.