> We consider a 2XX (Success) and 3XX (Redirection) status codes successful

I feel like this is flawed, especially considering 1/2 of the successful responses were 3XX. It's possible that they had just linked a short URL that was a redirect, but it's also possible that the product was shuttered and a redirect put in place to a replacement product, the company homepage, or even an acquiring company. I don't think there is an easy way to tell based just on the response code, and I'm not sure you could even programmatically determine it unless you had samples of what the pages looked like on launch day (maybe compare today vs the Internet Archive?).