Yes it does, they monitored infection rates - 1.9% in mask users and 2.1 % in non-maskers
Do you know what confidence intervals are? The study states "Although the difference observed was not statistically significant, the 95% CIs are compatible with a 46% reduction to a 23% increase in infection."
Their first limitation listed is "Inconclusive results".
So anyone looking at that study and claiming that it puts to bed any idea that mask wearing protects mask wearers. doesn't know what they're talking about.
Read the article, as others are free to, don't rely on me, anyone interested should read it at source.
I did, I have, and it doesn't say what you are claiming.
Here's a quote from the study conclusion "Yet, the findings were inconclusive and cannot definitively exclude a 46% reduction to a 23% increase in infection of mask wearers in such a setting. It is important to emphasize that this trial did not address the effects of masks as source control or as protection in settings where social distancing and other public health measures are not in effect."
So it has nothing to say either, about the protective effect or otherwise of masks in a classroom where social distancing is not being observed.