100% not related is probably too strong, but reports say they've broken readership records and have added ~90,000 subscribers since March. It seems much more plausible that the collapse of the events and ad businesses due to current economic conditions are the driver.
Both can be true. Ad revenues have been hit by COVID for sure, but the remaining ad dollars have gravitated toward higher-quality and more credible news sources. Clickbait and hype merchants like VICE, Buzzfeed, and latterly the Atlantic (the Buzzfeed of the Aspen Institute set) have suffered disproportionately.