Over the past year there have been a series of fixes and updates for Maya and Arnold. Including interface fixes, rendering updates, and the addition of new Arnold Shaders like the aiToon (shown above/top). You can update Maya 2018 (student version) for free by going to your Autodesk account and then 'Management' (above). Under your Maya license you'll find 'Updates & Ad-ons'. From the list select Maya 2018.4 update (the latest). There has been no news about Maya 2019 - although I suspect that will be announced very soon - so I'd recommend upgrading before the start of the academic year.