It’s also not that uncommon of an acronym in web tech, all the first results when searching “PWA” are consistent and it’s a very common way to refer to that technology. The term PWA has made the news in tech channels a few times before (like when Firefox discontinued support for PWA on desktop).
Even if they said “Progressive Web Apps” it would not have been immediatelly clear what that means for anyone who is not familiar with what PWA is. It’s also not the only acronym they use in the article without explaining it (eg. “API”, or “iOS” which is also an acronym on itself), it just so happens that it’s likely not a well known one in this particular lemmy community where the article was posted. The author advertises himself as a writer dedicated to web technologies (PWA and Web Component in particular), so it would be silly if he has to explain what those are on every of his posts.
And please, get all countries to actually start properly accepting ISO 8601 format for dates as a mandatory universal standard…
Obligatory reference: https://xkcd.com/1179/