On the contrary. It appears that Bud Light sales continued to fall.

https://sherwood.news/business/beer-bud-light-market-share-b...

Budweiser stock did recover, but they haven't (afaik) repeated the behavior that got them boycotted in the first place. It appears that this boycott achieved exactly what was sought.

I'd agree that this is a rare exception, and that boycotts are almost never successful. But this really is an example of that unicorn.