The guy on YouTube who just recreated the formula of Coca-Cola with HPLC & etc should take a crack at it

Perfectly Replicating Coca Cola (It Took Me A Year) by LabCoatz https://youtu.be/TDkH3EbWTYc

Sorta, it’s a mix of mixtures of molecules so you also need to consider the makeup of whatever compound it’s made with (but it’s probably something dumb like kerosene).

Reality is you’d want to make something with similar physical characteristics and call it a day. Kinda like how we don’t bother with hplc on gasoline, you just fill your car with something that meets the specs and get on with life

To some extent. There are limitations on the technique, including, but not limited to, not determining the relative concentrations and not detecting all components. The WSJ article actually links to an older Wired article about doing gas chromatography and mass spectroscopy on WD-40 and the results: https://www.wired.com/2009/04/st-whatsinside-6/

Related, somebody recently did this for Coke. There's a video on YouTube (I'd link it but my anti-procrastination filter is on).

But yes, I strongly suspect a motivated party could use analytical chemistry to work it out.

The components are on the MSDS (albeit only the CAS codes not the specific chemical), only the percentages seem to be a trade secret? Basically a light carrier oil mixed with kerosene-esque solvent. I almost feel the secrecy is part of the marketing ploy, since w-40 in particular isn't the "best" tool for any job (there are better standalone degreasers and penetrating lubricants). No one who cares enough about the exact composition would bother using wd-40 in the first place.

Knowing all the molecules in it might be only a minor step towards actually making it, especially since some inputs of production might not be present in the final product.

Trying to come up with that would result in WD-38, WD-41, etc.

Can't read the paywalled article, but Water Displacement formula 40 seemed to be the best of the formulas for being a lubricant.

It probably wouldn't be that hard. This mystique is mostly marketing. I mean it's not like WD-40 has no competitors on the market. It might not even be the best.