I used to work for Cadbury, here's some chocolate facts for you (former) dairy milk fans:
Cadbury only uses fresh milk (all other brands use dried milk) so the milk local to the factory is only used. So in bournville Birmingham it's brummie milk, Dublin it's Irish milk and Poland it's Polish milk. The grass affects the milk taste, and so the chocolate taste. That's why even pre takeover the uk & Irish choc tasted different.
You can adjust quantities in a recipe without changing the recipe. Hence they aren't lying by saying it's the same recipe post takeover. But those of us with functioning taste buds know that it tastes different. My bet is the non coca fat content has increased, or changed to cheaper fats.
Egypt, South Africa- yes the export market chocolate did have additives to help it have a higher melting temperature. I think this was all made in Australia, I'm not certain.
The shape of the moulds- from edgy squares to rounded lumps. Yes what is that all about eh? I think it's a new brand manager that doesn't care about the brand heritage. And it's very expensive to change moulds so someone deemed it worthwhile.
The brand managers were always judged on sales, brand growth, market size as well as profitability. So maybe now under new ownership the decisions are more based on profitability.
Bars made in Dublin for you hunt out for enjoyable consumption- snack, spira (I think both have been delisted) wispa, twirl, Cadbury dairy milk golden crisp, mint crisp, tiffin, all in the foil & band old style wrappers. Though I noticed they have more flow wrap plastic now, which is a pity. I think the foil wrapper makes the chocolate taste better.
And since qualifying as a chocolate taster, I now have done some wine exams 
It's sad though the chocolate is not the same.
My DH works in Belgium sometimes and he brings home Leonidas or Boulanger fresh chocolates. Much superior