We found Nomi in Valdrakken on the Dragonflight Alpha!
Nomi left Pandaria for the Dragon Isles because dragons favor a style of cooking for which he shares a certain affinity (most likely burnt food).
Nomi can be found in Valdrakken, the main city of Dragonflight.
The Pandaren has the following dialogue:
Hello, friend! I have come to the Dragon Isles with a hope in my heart to further hone my craft.
From what I understand, many dragons tend to favor a style of cooking for which I share a certain affinity.