If we are talking about the mandela effect theory then this isn't about logic. Mandela Effect theory started when huge masses of people shared the same memory of Nelson Mandela dying in prison and it all came out in the open when the news reported his death years later than what people remembered. The theory is about altered reality, not altered products. People in very large numbers have different memories of reality. Since then a bunch of easily explainable misunderstandings started getting labeled as mandela effect when they clearly aren't. So the waters got muddied and like many things when it went mainstream it caused a bunch of confusion and most people don't have an accurate understanding.

One theory behind this phenomenon called "mandela effect" is that cern may have done something when it first got turned on that merged more than one timeline together, so some people being from one timeline have a different collective memory than those from the other timeline. This is also backed up that many people remember our solar system being in the outer sagitarian arm of the milkyway, and now they say we are located somewhere closer in the middle, and that we've always believed that (and not just an info update)