Passcodes
This is a very unclear addition, but much has been added revolving around 'passcodes' which appear to be redeemed for items and are involved with the store.
It's our current theory that this is a way for Niantic to give out coupon codes for redeemable items in-game. This would make sense when considering Niantic or sponsors would then have the ability to give out redeemable rewards in-game, for the first time, via codes.
This may be a misinterpretation of the code, but there is clearly much added about redeemable passcodes.
On alternative explanation, for example, might be that these are simply a developer-side tool to auto-populate accounts with items for testing, etc.
...but our money's on in-game swag redeemable via acquiring passcodes. :)