The tobacco industry has a rich history of trying to manipulate public opinion in their favor, and this article and authors’ undisclosed conflict of interest fits that pattern well: a study shows cigarettes are actually good for you in some way, and might even save you from the current pandemic; and then whoops, authors were getting paid by the tobacco industry, and then whoops again, they didn’t mention it when submitting for publication.
If the study was retracted even though the CoPE guidelines don’t require a retraction, it implies to me that this case was more egregious than just some protocol mixup or forgetfulness. The most generous reading is that the retraction was made out of an abundance of caution and concern for the journal’s reputation. I suppose that’s possible, but I don’t see any further evidence in favor of exonerating the article, especially knowing the industry’s history.