I would assume they would add additional pages to the vault, as it works with your friends list and currently players list.
Another possibility is that they could split the vault into three different vaults. One for inventory items, one for weapons, and one for armor.
EDIT:
Many thanks for all the replies and opinions!
Can we make it to the trending page??
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Why limit the vault? Most people like saving their earned weapons in their vault as trophies. I love storing faction weapons in there, especially the blood red New Monarchy weapons, although I rarely use them.