This being an article from a British newspaper, it wouldn't use the term "candy bars" - they're all considered "chocolate bars" in the UK

Yes in the UK 'candy' means what you would call 'hard candy' (although most people would probably use the term 'boiled sweet' instead), and what you would call 'candy' we call 'sweets'. A 'chocolate bar' is any sweet enrobed in chocolate.

Be careful with your definition...

A chocolate bar is generally something that is vaguely rectangular (longer than it is wide), has chocolate as it's outer layer, and would take multiple (often many) bites to eat.

If I take a sherbet pip and dip it in chocolate, it is not a chocolate bar good sir! :-)

Sure, we call them chocolate bars in Canada also. The point I meant to make was, whatever we prefer to call those popular/fun/iconic products in the article, they don't represent great chocolate. Neither then nor now.

'Chocolate' is short for 'chocolate bars'. The title isn't 'great chocolate', it's 'great chocolate [bars]'. To many people these are great chocolate bars, demonstrated by their longevity and continuing popularity today.