If you are asking "if I post a copyrighted video on Discord, is that a problem? "
https://discord.com/terms (for all the terms ) under rules of conduct :
As an example, you agree not to use the Service in order to:
violate the contractual, personal, intellectual property or other rights of any party including using, uploading, transmitting, distributing, or otherwise making available any information made available through the Service in any manner that infringes any copyright, trademark, patent, trade secret, or other right of any party (including rights of privacy or publicity);
