It looks to me like legalese intended to protect the company from lawsuit in case the wearer contracts Covid-19 despite wearing a mask.
The data, however, is showing that the use of face masks does reduce transmission of virus.
The "intuitive opinion" held by many "that the use of face masks does reduce transmission of virus" may have some merit and be correct to some small degree, however there have not yet been any significant studies that confirm this opinion. The studies that have been done and reviewed in this thread do NOT confirm that opinion, and present evidence that the "reduction" is probably minimal.
The following report by By Dr. Russell Blaylock, MD – May 13, 2020 highlights the risks of hypoxia and/or hypercapnia from the use of face masks. I quote just one of them here:
"The importance of these findings is that a drop in oxygen levels (hypoxia) is associated with an impairment in immunity. Studies have shown that hypoxia can inhibit the type of main immune cells used to fight viral infections called the CD4+ T-lymphocyte. This occurs because the hypoxia increases the level of a compound called hypoxia inducible factor-1 (HIF-1), which inhibits T-lymphocytes and stimulates a powerful immune inhibitor cell called the Tregs. This sets the stage for contracting any infection, including COVID-19 and making the consequences of that infection much graver. In essence, your mask may very well put you at an increased risk of infections and if so, having a much worse outcome."