I remain hopeful, too. Even with the survival of moas being unlikely, I still think there are some relatively large animals that remain undiscovered or whose survival remains unknown. There almost certainly aren't any surviving glyptodonts, or steppe or woolly rhinos, or diprotodonts, or other fauna well over a tonne that has survived hidden since the Ice Ages, but let's look at the last few decades. Dingiso, which are a fairly large tree kangaroo, were not discovered by scientists until the 1990s in the mountains of New Guinea, and they're relatives of the Wondiwoi tree kangaroo, itself almost certainly rediscovered last year. Myanmar snub-nosed monkeys and kipunjis are both fairly large primates discovered by science this millennium. Saola, while extremely rare, were discovered in the 1990s along with some muntjac species in Southeast Asia. None of these animals are sauropods or mammoths, but they're still reasonably-sized animals. Even the Laotian rock rat, while not as big, is a fairly recent and evolutionarily unique discovery in the same general part of the world. I think there are still some surprises in the rainforests and mountainous regions in places like parts of South America, New Guinea, or the mountainous regions of Southern Asia.
So I look forward to seeing what other animals on that "Lost Species" list turn up alive, because it's not a question of if it will happen, but which ones and when.