vegan

I think this comment's assertion is overly simplistic: the intention (not the only intention; I'll get to that) isn't for any given omnivore who reads this article to say "Oh wow, I was so wrong all along. We must liberate the animals!" and instead just to move the needle. An ideology isn't just a single binary switch in a human brain; it's a complex set of individual beliefs that all support a common narrative. Each constituent belief not only reinforces the overall ideology, but each belief also subtly changes that overlying ideology.

"Veganism is unhealthy" is itself an ideology that supports the ideology of carnism. As you noted, this article is extremely well-cited to obviously reliable third-party sources. Those scientific sources can chip away at, coexist with, or even supplant some of those underlying beliefs, and that does weaken the "veganism is unhealthy" (and by extension, the carnism) ideology. Even when I was vegetarian for example, I was majorly concerned over the healthfulness of a fully plant-based diet; after stumbling down a rabbit hole and looking through meta-analysis after systematic review, however, I began seeing veganism not only as just "not unhealthy" but as actively healthier than what I was eating. This can even be as simple as getting omnivores to just occasionally substitute some of their animal-based foods with plant-based ones. Because that's still a win both in the immediate term and in the sense that it chips away at a habit of eating animal products, where "Eating plant-based is too hard" is itself an underlying ideology of carnism. I'm sure there are unicorns out there for whom this article could actually be the final straw, but I at least agree those people are somewhat rare (albeit a vegan community is likely to have a higher concentration of omnivores thinking of pulling the trigger than the general population).

In addition to I think just being wrong on the point that this can't be directly persuasive to omnivores, one major point that I think your comment is overlooking is that more vegans being educated is unto itself a good thing for the quality of activism. When vegans have actual, credible information ready to go when someone makes an anti-vegan talking point, sure it's still going to be hard because the overwhelmingly dominant societal ideology is carnism, but it's going to be a lot easier to counter with highly credible science that directly shuts their argument down instead of just sticking to low-quality information like personal anecdotes.

Finally, the point I made in the first two paragraphs cuts both ways – veganism is an ideology, and that ideology also has underlying beliefs. The affirmation through high-quality sources that a plant-based diet is not just healthful but actively more healthful in many substantial ways than an animal-based one helps especially newer vegans to strengthen that ideology by strengthening the underlying beliefs, and that makes it both something that's easier to stick to and something that's more appealing to share with others.