@SmokeSauce, thank you and I checked in with the team. The end result is a little bit different but ultimately once somebody opens all Stages of the Armorer Chest, it will give all the needed materials to upgrade to TB 6.
The Armorer's Crystal Chest has a set number of upgrade mats as you see there. Since you open up to Stage 9, you'll get 9 missing Armorer's Crystal Chests in your in-game Mail soon. Each Stage after will continue to give (1) Armorer's Crystal Chest. Opening all 12 Chest Stages will ultimately give you: 2,400 Soulstone Crystals, 2,400 Sacred Crystals, 600 Moonstone Crystals, and 600 Elysian Crystals.