Are children's food preferences getting very sophisticated?

Depends on how the kids are introduced to different foods sounds like your lot have had experience of lots of different types which can only be a good thing. My youngest granddaughter is similar she will try anything and just loves to choose her own meal wherever she is taken , she loves sea food and will happily order squid, mussels and all kinds of sushi. Some of its not to my taste.
Kids get to travel abroad much more which helps them to sample new tastes..

It depends entirely on the family attitude to food and what they make available to their children.

Smoked salmon and olives are my 7 year old DGS's favourite - there's posh!

My small grandchildren devour freshly picked, lightly cooked asparagus when it is in season. In fact anything that they pick themselves from our allotment is appreciated.

Oldest GS has munched on dried chilli peppers as a snack since he was 3. Youngest brother, at 9, became a dab hand at producing sushi, his friends enjoy having a go with him when they come to tea!
A couple of Christmases ago 'Cake in a Mug' and 'Meal in a Mug' books they found in their stockings got plenty of use.

Ours have certainly been exposed to far more choice in food than I ever was. They all love a roast and pretty much anything homemade. The two oldest like fish especially smoked mackerel or salmon.

The two youngest will try anything but are currently at the stage where as long as you're eating it too they'll give it a go.

We took our 9 year old granddaughter swimming at our gym recently and we decided to stop for lunch after. Grampy handed her the children's menu which she read, and then asked to see his menu.

When done she handed it back and said 'I'd like the salmon on wilted spinach with sweet potato mash please'. No chicken nuggets for that girl !!!

I wonder why Gransnet has labelled this thread (on Facebook): "Are children becoming more picky eaters?"
I always thought that "picky eaters" were those who will only eat a small variety of foods and are unwilling to try anything new, whereas most of the children being described on here are the exact opposite of that, aren't they?

My GC are much more adventurous than I was as a child, and will try most new foods to see if they like them. Their parents encourage this and give them a very varied diet, though I suspect that they would still eat pasta or something with chips at every meal if they were given the choice!
They came for a sleepover on Thursday, and when I asked them later what they had enjoyed the most, I expected them to mention the torchlight wildlife walk we did in the woods as it was coming dark, but DGS (age 4) instantly replied "dinner", which had simply been fish, chips and peas!

Oh, and the DGC have always grazed in my garden from spring to autumn, helping themselves to whatever fresh fruits, vegetables and herbs they can find. Interestingly, there are quite a few vegetables that they will happily eat in large quantities raw, straight out of the ground, yet turn their nose up at when cooked and / or served on a plate!