1. Almost stopped reading at anyone can do it, it doesn't need Sharingan and that Hyugas could do it better.
2. We don't know how all seals work. We know Naruto's has a key, effectively, Naruto has a key that allows him to open the gate and let the Bijuu's power unleash. The issue here isn't if the seal is there or not, it's still there, just open. The issue is, can Sasuke push the Bijuu back into the seal, and keep it shut? Ideally, yes, but now the question becomes can Sasuke's suppression be everlasting, or can Naruto just open the seal again. Can Sasuke place a new lock, or just close the lock that's already there, which Naruto has the key for. And quite frankly, we just don't know. At this point in time, we don't have enough information to say.
I could say he can, you could say he can't. We'd be equally right, and equally wrong, because both of us are just guessing.