Probably because he is the Kyuubi's Jin and he wants to kill the Bijuu.
And i suspect that the Sage told him that if you kill the Bijuu , they will just regenerate so its pointless , that's why i think Sasuke's attitude towards Naruto will change but he will still have his own solution for...
I think the Sage reasoned him a bit , easing more the job on Naruto's part ( first Itachi then Hashirama then Hagoromo , talk about reasoning ).
To put it simply i think that they won't have a death match for the Hokage title.
First of thank you for your feedback.
I don't think the Sage shared half his power with a corrupted Sasuke.
And he will probably tell Naruto that they might have the same goal but they are not the same ( a foreshadowing for their battle over the Hokage title )
But oh well , let's wait and...