Does divorce take effect and count as one pronouncement if the wife speaks with her maternal uncle after reconciliation, given that the husband swore that she would be forbidden to him like his mother and sister if she spoke with him, this oath being made in a state of anger and with the intention of divorce?

A man's statement to his wife: "You are forbidden to me if you do such-and-such or if you do not do such-and-such" is an implicit declaration that depends on his intention. If he intended divorce, or ẓihār, or īlāʾ, then what he intended occurs. If he did not intend anything or merely intended a threat, then it is an expiable oath if broken, and this is the view of the Shafi'i school. If the swearer adds to this phrasing a comparison to his mother or sister, then it is most likely that it constitutes ẓihār. This is the fatwa (definition) given by the Hanbalis and preferred by Shaykh al-Islam Ibn Taymiyyah. Ibn Qudamah adduced as evidence that whoever says: "You are to me like my mother's back, unlawful" (أنتِ علي كظهر أمي حرام) has made an explicit declaration of ẓihār. Accordingly, the husband must perform the expiation for ẓihār. As for anger, it does not prevent the occurrence of ẓihār or divorce as long as the swearer is aware of what he is saying and intends it. Regarding your statement: "after hearts reconcile," this refers back to the husband's intention: if his motive for swearing was a specific reason that has since ceased, then ẓihār does not occur by your speaking with your maternal uncle. If there was no specific reason, and his true intention was to prevent you from speaking with him for the rest of your life, then ẓihār has occurred, and there is no meaning in reversing it, even after hearts reconcile.