I have also seen Versace and Gucci versions, maybe some others I don't recall. I think they chose Balenciaga because the name itself feels kind of unusual and it fits the wizarding theme.
That being said, if it's an actual marketing campaign, then it's been quite successful at least in my case, as I never even knew Balenciaga existed before seeing these vids... Then I took a look at what they actually sell and promptly concluded I would never buy from them, even if I had the money lol.
https://www.balenciaga.com/en-us/trash-bag-large-pouch--whit...