There are limitations to donghua that can be accepted to the site, notably there should be significant creative control of the titles from Chinese and Taiwanese studios.
Even if a title is animated by these studios, it may not be added to the site due to significant creative decisions being made by western companies.
Ling Qi was produced by the Chinese studio Haoliners Animation League and the primary staff (director, writers, etc.) are also Chinese. While this show does have a Japanese dub, its original language was in Chinese. Due to its production, it would be classed as Chinese donghua and not a Japanese anime.