The term "uncle" typically denotes a familial relationship, and whether someone remains your uncle after a divorce depends on how the family views and maintains those connections. Legally, if your aunt and her husband get divorced, the legal relationship between you and the former husband (your uncle by marriage) is dissolved.
However, in many families, relationships established through marriage can still be considered significant even after a divorce. People often maintain emotional connections with their former in-laws, especially if they have spent significant time together and developed strong bonds during the marriage. In such cases, individuals may continue to refer to their former brother-in-law as "uncle" out of respect, affection, or family tradition.
Ultimately, the use of the term "uncle" after a divorce can vary from family to family and is influenced by cultural, personal, and emotional factors. Some families might continue to use the title, while others may not. It's essential to remember that family dynamics can be complex, and individuals should be sensitive to the feelings and preferences of all family members involved.