Yes, i am a sasuke fan but lets be logical.
hitting naruto with amatarasu is going to be very difficult because of his speed. you gotta remember, sasuke must focus his eyes on one spot to use amatarasu on something or someone.
sasuke used up chakra and it hurt his eyes to use amatarasu over and over again, but now he has EMS. we dont know for sure the full extent to his power and amatarasu usage now that he has EMS.
we already know for a fact that he is able to change the shape and form (like when he was against raikage) and control amatarasu better with his MS, now that he has EMS he'll obviously have even better control of it.
Naruto now has control of the kyuubi, as seen against Tobi, and has obviously become more like his father by perfecting the flying thunder god (as shown against raikage) so the full extent of his power is also unknown.
I hate that people use the chakra threads saving the samurai thing as a way to counter sasuke. the flames were burning the armor and almost burnt through it, the armor was just taken off but was still burning. all that happened was the armor was removed, we dont know for sure if it can burn through a strong chakra shield. but, then again he did burn raikage while he was using a lightning chakra shield.
i think its best to just wait and see when Naruto and Sasuke fight cause they are very even.