So the more I've talked with various individuals and looked into this, the more I'm starting to realize that perhaps Airbags are not "lifetime" objects like the industry originally thought.
It may turn out in the next few years that Airbags will have a set lifespan. This seems to be the same opinion of some others in various positions I've spoken to as well. What that will mean for older vehicles is yet to be seen, we (as in the consumer, technician, and relative public outside of the NHTSA, Affected Manufacturers, and Takata) lack a lot of information on what's going on. As far as I know, the airbags we've recalled may end up being recalled again in a set amount of time for the same issue (this seems to have been indicated to some Honda owners/Technicians who passed it along to me, I haven't verified it yet), but if the issue is that the airbags do just degrade over time; that falls inline with that theory.
Much of the issue with the Takata airbags is that the descant or lack there of (in the older ones from my understanding) does not last nearly as long as they had originally hoped. So the airbag recall is preemptive in that they have roughly calculated how long it will take the inflators to degrade to a "potentially unsafe" state. So you'll see all the very humid areas get their inflators replaced first and drier areas following after that just like they have done with the current airbag recalls. The more important question that I can't seem to get a solid answer on and seems to be reinforcing the more common opinion that airbags may be less than lifetime is that even "new" airbags such as those in the 16's are being preemptively thrown into a future recall. Which means either they have not figured out a solution at the factory or that a solution may not be possible beyond setting an expiration date? More importantly what about the other airbag companies? Like I said, there's a lot of missing data that would help clear things up...