Well it's pretty obvious that new players now get fitted out with a variety of gear so that they can be more wide-spread with what they use, allowing them access to some great stuff early on to consider upgrading (entire Cobalt set, a Brandish, Skelly armor, etc.) So here's two new items that could be given out to them:

Transient Weapon Slot Upgrade (7 days) and Transient Trinket Slot Upgrade (7 days). These would do exactly what you think they'd do; they're a weapon/trinket slot upgrade that lasts for one week. They could be similar to the old Mist Tanks in that you only get them with certain missions. Specifically, you would get a Transient Weapon Slot Upgrade (7 days) as a mission reward for the rank 3-1 mission, Blades of the Fallen. As a new player, getting that Blast Bomb is really cool and all, but it is usually replaced (assuming it's even used at all) as soon as the person obtains the Calibur and Blaster (from the Blades of the Fallen mission). Rewarding a new player with a limited-time weapon slot would allow them to use their new Blast Bomb along with their Calibur and Blaster. This would give new players more variety, and it could also show how having more than just two weapons can be very useful at times, so once the week is up up players may be encouraged to buy a Weapon Slot Upgrade (30 days). How they get the Energy for this isn't being discussed.

Similarly, the Transient Trinket Slot Upgrade (7 days) would be obtained from the rank 4-2 mission, Monstrous Research (not to be confused with the Monstrous Research mission(s) from other ranks, or the prestige version). Just like the Weapon Slot Upgrade, this would obviously only last for one week, giving new players a use for their new trinkets that they obtain (from the rank 4-2, rank 4-3, and rank 5-1 Monstrous Research missions, each one of which rewards the player with a trinket. Completing the latter two missions would not reward the player with a Transient Trinket Slot Upgrade (7 days), only the first one would). Again, this could show how having trinkets can be helpful, and it could encourage buying a Trinket Slot Upgrade (30 days).

These upgrades would obviously be bound to the player, and would not stack with already existing weapon/trinket slot upgrades. Trying to use the Upgrades while you already have a weapon/trinket slot upgrade active would simply not give you the option to Upgrade nor would it give you the option to Extend until xxxx.

EDIT: Changed the duration to one week instead of two days. Changed name from "Cracked" to "Transient".