Unfortunately, no. If a file has been uploaded to the Materials section of a Stellar site and has been marked with a copyright flag, that file will only be available during the semester for which it was intended due to copyright restrictions.
Depending on the material, cross registered students who use Touchstone Collaboration Accounts may not be able to access any restricted files on a Stellar site even before the site is closed. It is strongly recommended for them to obtain MIT Kerberos Accounts. More information see Stellar Access for Cross-Registered students.
If this article does not resolve the issue, please use the [Stellar Recon page].