Me neither. I read a couple of descriptions of striped cuckoos. None mentioned this tidbit and that made me suspicious.

On the other hand, I did find this: https://www.thenakedscientists.com/articles/science-news/cuckoo-chicks-earn-their-keep

It includes a picture of a nest with a cuckoo chick and, although it doesn’t look like a pine cone, you can easily make out the speckled feathers. Also, the article is interesting in asserting that the cuckoos’ parasitism isn’t all bad.