If anything, I'd love just a funny side story of not just Sasuke, but the Uchihas in general. It would be funny for me to see a Chibi Obito, Madara, Itachi, ect in a manga, just like how Spring Time of Youth was.
It seems as if the source who said that The Last is between Chapter 699 and 700 is correct. Because some of the character designs in 700, like Shikamaru's and Gai's are older and more mature looking in 700 than in Last.