Another good read - this time from SmartCompany As per @CEM's...

Another good read - this time from SmartCompany

As per @CEM's comments, which I agree with, a smart marketing strategy will be required to engage the audience while the short-term nostalgia surge lasts:

From the article:
Treats need new yow factor

Despite Yowies resting warmly in the memory of many 20-30-year-olds, marketing expert at Marketing Angels Michelle Gamble believes the brand will need to make the chocolates relevant to new audiences.
“The original audience has moved beyond the Yowie brand. They’ll probably talk about it and buy a few, but the company needs to do something to give it new life,” Gamble tells SmartCompany.

“They’ll need to grow the brand and get good penetration. It has to be relevant to a younger generation as well.” Gamble believes this can be achieved by getting the brand in the right channels, such as popular “corner store” retailers like 7/11.

“The corner store mentality still exists in kids these days. They might not be spending a dollar on a mixed bag of lollies anymore, but they have the same purchasing behaviour,” she says.  “Support this with good marketing that millennials are using, like YouTube or Snapchat.”

For brands hoping to employ a bit of nostalgia-based marketing, Gamble notes that relaunching a loved product isn’t the only way to do it.

“Nostalgic advertising can work well for products businesses are still selling or are still being bought. It’s a great way to get old buyers coming back,” Gamble says.  “Nostalgia can be fleeting so you’ve got to make it relevant.”