This Was Considered Comically X In Y - This was considered a "too big to be appealing" butt in 2004...

Helen: sigh I guess I did put on some weight like bob

the internet : Oh, on all the right places

It depends on the era, the generation, the customs of the time. If you look at Renaissance paintings or ancient Greek statues of what would be considered beautiful women, you'd notice that both have a trend into liking women with a bit of meat on them, the first more than the latter.
I learned that women from more than a century ago used to wear these things called "bustles" underneath their dresses, to make their butts look bigger

I've also found these, from the the 20th century


I think the "very skinny" beauty standard entered around the 60s and continued on to the early 2000s. I very distinctively remember various ads, movies and cartoons shaming big butts because they would imply that the woman with the big butt was fat.
You can witness it firsthand by watching old films and music videos, early 2000s especially.

In short, yes, the "thicc" preference is something new and not everybody has mentally adjusted to it.
Not everybody prefers it.
Some cultures more than others.