How is this related?

I mean I get it targets the BEAM, but Gleam is a programming language, Lumen is a VM.

The vast majority if code that gets used on this will be Erlang and Elixir. At least for now, those are the two languages on the BEAM with traction.

It's interesting to see how Caramel, Gleam, LFE, etc, will develop, though.