Having read the article, it doesn't actually say "vegan junk food is worse than regular junk food".
The article at length explains how a vegan diet can lack various things like proteins and iron, which are readily available in non-vegan foods. The strange premise is that if you're eating a vegan burger, you must be a complete vegan.
A proper title for this article would be "don't go 100% vegan unless you know how to stay healthy on it".
That's been known for a very long time, but with all the new vegan products, by companies who just want your money not your well-being, it is worth reminding people that going vegan isn't a simple thing. It's not "healthier" if you aren't doing it right.
But I think that if someone is a real vegan, they know this already - because it takes research to know the problems with meat production, and how to replace it. It takes effort to get there. A vegan who buys a vegan burger already knows it's a "fast food", very different to a proper meal.