Naruto doesn't have rikudou mode anymore. Anyone who denies it, is in denial.
-He can't fly anymore. He could've flied to save Hinata in the last, but he didn't.
-He doesn't have the black orbs anymore
-His skin doesn't glow on RSM, and every time he uses the form as an adult, his skin glows, exactly like BSM, BM and KCM.
Abscence of evidence is evidence of abscence. Kishimoto is too lazy to draw Naruto in RSM, and maybe he just forgot about it, or he doesn't like it. Does it make sense? No. But Naruto in RSM could rival Sasuke and the 9 bijuus. Sasuke loses the Bijuus.. so naruto has to lose something aswell.
Sasuke clearly says on VOTE 3 to naruto, that he has very little rikudo chakra left.
And correct me if i'm wrong, but every time Naruto lost a so6p black orb, it didn't grow back. He just went losing those powers little by little.