The only thing that stands out in that piece is that they're collecting advertising device IDs. Those IDs are anonymous and resettable. Snapchat doesn't need them internally since they have a more persistent identifier, i.e. snapchat user ID.
It might be that they want to pass this ID into programmatic platforms. Some systems treat them as pseudo-cookies for frequency capping, measurement, and basic targeting.
It might be that they want to pass this ID into programmatic platforms. Some systems treat them as pseudo-cookies for frequency capping, measurement, and basic targeting.