It's the real thing

We have to be careful with this one.

Coca-Cola scrapped the brand "Coke Zero" amongst falling sales due to it's growing army of health-conscious consumers. The Mandela Effect here is the fact many remember the name "Coke Zero" actually appearing on the cans and bottles for years before this, when in fact all references today show it only showed the full name "Coca-Cola Zero".

One YouTube poster even claims he actually saw it change in front of his eyes.

Some are saying it's just the common way of abbreviating Coca-Cola, as in "fancy a Coke?", but applied to Coca-Cola Zero, so that becomes "fancy a Coke Zero?". Others are definitely not convinced...

Branding

Using "Zero" to indicate a food product did not contain something which you'd not want anyway, such as sugar, fat or "e-numbers" became a popular trend in the 1990's.

One problem with this is the way people drop the "cola" part of the brand in everyday language, as in "fancy a coke?". This being so established means any addition would tend to be similarly dropped, so if there was a Coke Zero people would normally still just say "Coke".