Paraphrasing: "In this paper, we reiterate previous assertions about how utterly boned we are as a species in the event that a nearby star has gone supernova in the last few hundred years."
There is also something about galactic habitable zones that is interesting: maybe the Fermi paradox is explained by alien civilization only appearing in galactic fringes, and therefore spread well apart.
I only read the abstract and conclusions so maybe this is covered in the paper - but based on some reasonable estimates of the damage done to organic matter by these x-ray bursts (and similar events) and of the time taken for life to evolve, I assume we could significantly improve on the Drake equation by updating terms which represent "probability of not being scoured from existence".