Alright guys, been browsing the forum for a while now and decided to share my opinion finally...
Obviously regarding the navcards and what I feel they may be for. Of course following what is highly expected that the navcard from one map will activate the reader in the proceeding map, confirmed by Die Rise. However, I have two suspicions of what will happen in the end.
Firstly, to state, I don't believe they will link the maps at all. It just seems unpractical to go from one map to the next. My theory revolves around unlocks.
After activating all of the navcards, could it be possible that we unlock the original zombie maps free of charge? After all, we have paid for them essentially twice now (their respective map packs in WaW and the final map pack on BO), so surely it would be considered ludicrous to pay for them a third time. So this could be a way for us to earn them through progress. Also, the BO maps could be released in the final BO2 map pack like on Blops.
Anyway, that's just my thoughts. I look forward to contributing more to the boards in future, so leave your opinions as you wish