In most cases, they are. But it depends on specific interpretations and the creators' statements.
The Madoka manga can be seen as canon to a large extent. However, there might be some nuances and differences compared to other related works that could affect this perception. It's a bit complex and can vary depending on individual perspectives.
The Madoka manga is generally regarded as canon. It follows the core concepts and storylines established in the main franchise. But sometimes, supplementary materials or alternate versions might introduce slight variations that could cause some debate among fans.