I don't know what it is, and the mark of a skilled birder is to know when to admit they do not know.
However, I do know that the chips Swamp Sparrow make usually have a distinct rich quality, which this lacks. The call in this recording is rather generic sounding, at least to my ear (does not mean that someone else might be able to identify it, but would require a lot of skill and experience), and it could easily be from a variety of species. Flight calls are often different from the sounds made on the ground, and often requires careful examination of the spectrogram to identify. The reason you are noticing a similarity to the flight call is simply because the flight call resembles a more generic sparrow seet note.
Its extremely unlikely that the recording would be flagged because the species is common and the general assumption is that you identified the bird through other means, and happened to record the chip notes. Identifying birds by their chip notes is very difficult and it's basically impossible to prove with certainty this didn't come from a Swamp Sparrow. Hence, if you claim it came from a Swamp Sparrow, it's not going to get flagged