It is highly important for medical workers to know this (because wards contain far more virus than any other place). For the rest, we have to bear in mind a few limitations outlined there, most importantly:

> To allow quantification, we conducted our studies by using a relatively high dose of virus, and under these conditions, it is possible that the protective capacity of the masks was exceeded.

And this:

> In our experiments, the virus was suspended in culture supernatant without fetal calf serum or was diluted with phosphate-buffered saline. Further detailed analysis will be required to reveal the precise relationship between the protective efficiency of masks and the components of viral droplets/aerosols.

I wonder if they are planning experiments with artificial saliva, like those people which tested the stability of the virus under sunlight did.