(More than likely) Yes!
Unsweetened chocolate is just that — Cocoa nibs and cocoa butter. No sugar, no milk, no crap. Just chocolate. It has a very bitter taste (that’d be the lack of sugar) but can be eaten as is. Most often, it’s added to baking recipes that also involve a sweet. I’ve never come across a non-vegan unsweetened chocolate brand. If you find one, let us know.