Lol it wouldnt surprise me at all, the ground work has been laid down, sakura trains under tsunade who has the byakagou or wutever mode she came up with which comes for her diamond on her forehead. seeing sakura has now gained the triangle on her forhead well 1 + 1= 2
Sasuke could have trained his curseark at ryouchidou or wutever and learned sage mode there during the timeskip and as kabuto said oro always wanted to gain the sage mode also oro wanted sasuke because his body is perfect for oros needs(ew).
and juugo has already confirmed sasuke is compatible not to mention juugos power comes from his body storing sage energy till he starts raging out or something i have to go back and read that part again but my point is sasuke was compatible with him so it makes sense sasuke is compatible with the sage mode.
Hey now that i think about it ever since being shot up wit juugo dna sasuke has been raging out killing samurai fighting kage danzo and everyone else,maybe being with naruto and the kages and everyone sasuke probly feels at peace in a way and will finnally break out of his juugo rage resulting in sage mode. haha
but seriously i wouldnt be surprised if they both got the sage mode