This issue about what asset types qualify as funding has been raised and answered in the previous fidelity thread. The delta offer is a part of the other fidelity thread and this thread does not mention a new offer by delta, maybe the two threads could be consolidated.

All of you are right that retirement accounts do not qualify as funding assets as explicitly laid out in the T&C's. If you need more help figuring out how to stack all of these fidelity offers check out my post 100k Miles With Fidelity