I think the initial work is impressive partly because of how broad the range of topics the partnership has tackled AND how young they are. They are barely into their post-doc studies and are already making progress on challenging problems in the graph theory and combi space.

Basically, its impressive to make this level of contribution as an undergraduate team AND if they keep up this level of productivity the "big" discoveries will come in the coming years.

Graph Theory in General is extremly useful for all sorts of algorithms [1]. What the application for this particular discovery might be is also unknown to me.

[1]https://mypages.valdosta.edu/dgibson/sjs.pdf