Sasuke has his old MS instead of his EMS at the end of Ch619

[Uchiha Sutona]

I think Uchiha's can switch between which ever mangekyou they want.. and i think Madara is too good for his original mangekyou lol. But who knows why sasuke didnt activate his eternal... it looks way more badass

 

[Casualty]

I believe he can choose which 1 he wants to use why are you guys minds so limited?

^ this

 

[Floydical]

Sasuke can't change between MS and EMS. Once EMS is activated, its a permanent upgrade to MS and you can't revert back. This is what is implied from everything we know in the manga, barring manga mistakes which I think this clearly is one.