I'd say it fits Wikipedia's definition of reverse engineering pretty well: "The process often involves disassembling something ... and analyzing its components and workings in detail."

It's JavaScript we can call it whatever ... reverse transpilation.

I bet there are a myriad frameworks to do it aswell.

Deobsufucizer.js Reverse-sj.io

are those concepts really that different?

reverse engineering is usually about trying to understand a partially/mostly concealed system/interface, while for this case everything is already visible, but hard to understand.

By that definition, analyzing compiled native code would be "un-obfuscating".

IMO, deobfuscation is a subset of reverse engineering - which at a push I would define as "taking a program from the form it is distributed into a preferred form for modification/understanding".

Seriously. I didn't think the article was going to be just prettifying a 1 liner by hand. Looking back, it's actually cringe-y that he calls this reverse engineering. You know what real reverse engineering is? Figuring out the code from the output image only.

Hold on - would you say unpacking something packed by e.g. UPX by hand (silly example) wouldn't be reverse engineering? This is just unpacking a packed program, which definitely is reverse engineering.