Success! Just finished speaking with Taylor from Microsoft's Xbox customer service. So he did confirm that the one code does include all the content along with the game. We were still confused that it did not appear in game. It turned out the additional content was pending for install but it does not appear where games are installed. This is what you must do:
1. At Home go to My games & app
2. Under games highlight Battlefield 1 and press start
3. Five options appear - "Pin to Home," "Go to game hub," "Manage game," "Uninstall," and "Help." Select "Manage game."
4. On this new screen you will find a summary of what is installed. (This is where I saw that only the game was installed and no additional content.) To the left of the screen you will see 4 options including "Ready to install." Highlight that.
5. Here you should have noticed that there are two options ready to install. This is where the additional content has been hiding! Go ahead and begin installing your Deluxe edition content along with the Hellfighter pack.
6. Enjoy! The content will appear in-game immediately.
*NOTE*
This problem has eluded the likes of EA and the Microsoft Store staff. In addition when we were working it out on the phone it wasn't like Taylor immediately knew to direct me to game management. It took some troubleshooting to realize that the content was just sitting there pending for install. The fact that it had not automatically installed was definitely unusual.
Big thanks to Xbox Customer Service for the assist. Taylor was prompt, patient, and super helpful. Haha gotta give credit where credit is due (^_^)
