Is the appearance of a light pink discharge, followed by its cessation, after a seven-month delay in menstruation, considered menstruation that prohibits prayer, or is it obligatory to re-perform the Dhuhr and Asr prayers?

The majority of scholars hold that the minimum duration of menstruation is one day and one night. What you saw is not considered menstruation, and you are obligated to pray Dhuhr and Asr without performing ghusl. As for the Malikis, Sheikh Al-Islam Ibn Taymiyyah, and Ibn Uthaymeen, they are of the opinion that there is no minimum limit for menstruation. Therefore, you must perform ghusl after the blood ceases, and you do not need to make up those prayers. You may follow whichever scholar you trust. The website's opinion is that of the majority.