Remember how Madara unlocked his Sharingan and only had 1 tomoe on each eye? He did not have Will of Fire
But when Obito unlocked his, he had two tomoe, this must be by the Will of Fire that made it stronger or Love, instead of hate.
Now hatred makes the Sharingan stronger, but I think strong Love or Will can make the Sharingan become even stronger.
So I guess Sasuke's EMS has gotten stronger just now