Now this started making sense :) I never realized it was named after a word for a projector. Perhaps because I didn't read the wikipedia article until now.
That's correct. The naming was due to it being initial built to show information (=info) on a projector (=beamer) at a German hacker conference to inform visitors about talks, tweets and more. You can actually see the very first public usage in this old image from 2012: Note the projection in the top middle: https://entropia.de/images/c/cf/GPN12-atarifrosch-20120609-0...
I think that Beamer is way older than 2012. I first used it around 2005 when I was learning LaTeX for the first time and wanted to use it for everything, incl. presentations.
https://en.wikipedia.org/wiki/Beamer_(LaTeX)