I wouldn't say that this is a new and never seen before trend, but rather just another kind of attractions next to the animals some zoos feel inclined to invest in. I can remember European institutions like the German Vogelpark Walsrode heavily investing in playground areas in the 1970/80s to draw more people in, and zoos like the ones in Budapest, Hamburg or Frankfurt did such things decades (sometimes even more than a century) ago. Currently, especially some American zoos (but also European) seem to build more and more features you usually find in waterparks or amusement parks(f.e. Columbus new Polar Frontier or maybe soon the big wheel in Zoo Berlin).
Of course these additional features might attract more visitors, and thus benefit the zoo financially (the standard argument). However, don't forget that this stuff is often rather labour, space and cost intensive (also in regard to the maintenance), and needs constant updates to be attractive. And whether this is useful in the struggle of some zoos to become more than just a place to take your small children to, is another question.
Honestly, if a zoo wants to invest in such a thing, why not? But make sure that this does not result to the disadvantage of the animals kept.