Is it permissible for a man to prevent his wife from appearing before and speaking with his brothers, even if she is wearing a hijab, and is this considered excessive strictness?

A woman must cover her entire body, including her face, from non-mahram men, whether they are relatives of her husband or not, which contradicts what many people do today. The Prophet, peace and blessings be upon him, said: "The in-law is death." The brother did well by preventing his wife from appearing before his brothers, and the wife did well by responding to the command of Allah and her husband. This is not extremism but rather a response to the command of Allah Almighty. This action should not affect your relationship with him, nor the relationship of your women with his wife.