I agree that the Cadbury's Milk Tray is a special kind of shit now. Quite bland and tasteless, and every one tastes virtually the same:- even the orange and the strawberry don't taste of much. Also gutted at the turkish delight being binned, and the apple crunch (that has replaced it,) tastes like a nasty bitter medicine. On the whole, they are pretty tasteless, and a bit greasy. Used to be my fave choccies, (a 9 out of 10,) now they barely scrape past a 2.
I have thought this for several years (maybe even 4 years,) as I have failed to enjoy them for that long (maybe longer...) and I seriously thought it was just me, and that I was imagining it, or my sense of taste was going ... Then someone got me a box of Dairy Box, and they were sooooooooo DELICIOUS!!! In addition, over the ensuing months, I found the bars of Cadbury's dairy milk OK still, and the flake and crunchie, so I figured it MUST be the milk tray that was not great.
Then over another few months, a few other people I spoke to said they thought they were shit now too. It was then that I knew the milk tray were substandard now. A neighbour of ours brought us a box round for looking after their cats for 5 days whilst they went away, (in mid January,) and we binned 70% of them... They were mostly vile. 
ALSO, I agree that rolos taste crappy too now. Sort of stale and with a borderline mouldy taste; ditto for kit kats. Double Deckers too don't taste great. Haven't tried many more choccie bars as I tend to stick with cadbury's dairy milk which still tastes good thankfully! So I don't know if any other choccie bars are tasting shyte now.
And I do still love the Cadbury's creme egg, and they still taste the same to me, even though they are not made with dairy milk now apparently.