It’s not statistically sound enough for ‘proving’ anything, but it’s significant to document a process and outcome. I think you’ll end up seeing a lot of n=1 publications in the next year as they get accepted (publication process can take a few years sometimes). Grants didn’t necessarily halt for the pandemic, but in a lot of cases it wasn’t possible to do in person studies (whether that’s because of IRB restrictions deeming the research non-essential or because it’s very difficult to convince remote students to come on campus if they do not weigh the importance of the research above their own safety).

The important part is they are transparent about the sample size and threats to validity due to that. It’s likely just a precursor to a larger study, but they want to publish something to carve out that section of research. Part of it is on the reader to think critically about how meaningful/significant the research is. Like if I read this paper, I wouldn’t think it’s important enough to post on reddit. If I read just the title and abstract only, I’d pass it on. A lot of people don’t bother interpreting the methodology and results.