Translation:

we have made a number of updates to our bar sizes and pack formats to reflect consumer demand

People don't by Mars because it's a top-tier, gucci product.

alongside considering wider external factors such as manufacturing costs and the price of cocoa

And if we stayed the same size, it'd be really expensive, because among other things the global climate no longer supports chocolate production.

TBF none of it is a lie. That's as close as corporate-speak comes to "yup we did that".