From the g*vine and what I can dig up, it seems like we'd probably get Itachi - Kisame, Deidara - Tobi, Hidan - Kakuzu, Neji - Tenten - Lee - Guy, Choji - Shikamaru - Ino - Asuma, Sannin Jiraiya - Tsunade - Orochimaru before going to a bunch of monthly release skillbook ninjas, amongst them Sage Naruto and Danzo should be close to last imo.

My prediction is based on this blog here, it has not been updated since forever, but it covers the timeline up until team Guy's breakthrough: http://huoying.duowan.com/1509/307555868490.html

The Sannin part was on another blog, but I couldn't find it anywhere (I cleared my search history too often). I think Haku, Sasori, Gaara and Karin was in that one, But since I can't find it...

Disclamer: This is pure assumption on my part. Take it with a grain of salt.