This actual answer according the the author realized after he already liked the name.

He created it intending to be +1 of APL. Accidentally came up with BQN instead of BQM. Sat with that for 1hr, really liked the name, then realized that it should be BQM which he hated, so he stuck with BQN.

That said, it's and incredibly designed language. I honestly have never read any language (especially not designed by a single person) with the level of creative thought as he put into BQN. Some really incredible insights and deep understanding. It's amazing reading his posts / documentation about it. The focus on ergonomics, brand new constructs and the consistency/coherence of how all of his decisions fit together is really impressive.

I'm somewhat sure the author actually mentioned that that was the intention, "Big Question Notation" and basically "apl" + 1. But he realized that it didn't match up

Supposedly it stands for "Big Questions Notation", but that could just be a backronym.

I’m hoping they pronounce it “beacon” but the off by one error jokes also just write themselves.

They were following a Fibonacci sequence.

It's just. So gross. Say it. Sudden interruption of slime coming up your throat. Like walking out the door into a spiderweb. Alphabetically I was mistaken but in every way that matters I was right.