Hell yeah I wish at least 15 chapters of Rikudou Sennin flashback... for all these days when we waited for his reveal.Tbh, I have trouble seeing the Manga reach 700+ chapters, unless we are treated with 40+ chapters of Rikūdo Gaiden =D
Kishi stated that there are 2 years of Naruto left,which makes roughly 100 chapters,so it can't end with more than 800 chapters.
It feels like anything after the war arc except Sasuke vs Naruto would be an asspull and so I feel lik it will end around 900 chapters