I don't watch that many cartoons these days so I can't say for certain but I think most of them still have moral lessons/life lessons hidden in them, I just think that the people making these cartoons have become more subtle about how they disguise them.
The cartoons of my childhood ( G.I.Joe, Transformers, He-man, captain Planet, etc ) were not very subtle subtle with thier messages. The few cartoons that I do watch these days ( Transformers Prime, Justice league Unlimited/Young justice, Avatar/Legend of Kora ) still have moral lessons/life lessons if you know where to look.
I would say that the one thing that has changed from my childhood is that back when I was young the good guys always won which always reinforced the idea the good always triumphed over evil and the good behaviour was always rewarded. A lot of today's cartoons are a lot darker in thier tone, it's not uncommon fro the good guys to be the under dogs for the vast majority of the shows run with the bad guys always being a step or two a head. As such it is a lot harder to spot these little moral lessons/life lessons because it seems like thier is no reward for being good or doing the right thing.