I always interpreted these results as transphonologizing a three-way phonation contrast into a two-way pitch + two-way phonation contrast, but I may be misinterpreting the text. I was especially looking at the abstract of the paper you linked, where they say that the pitch distinction is between aspirated and lenis. I thought varieties like Seoul Korean had the following contrast now.
Long VOT
Breathy V
High F0 on V
Aspirated Stops
Yes
Yes
Yes
Fortis Stops
No
No
Yes
Lenis Stops
?
Yes
No
So in a way, the whole three way system is transformed. Aspirated stops become aspirated with a high pitch on the following vowel, fortis stops become non-aspirated with a high pitch on the following vowel and lenis stops become (maybe) aspirated with a (definitely) low pitch on the following vowel.