Why should the yāʾ in «وَلِيَ» not be prolonged as a madd letter?

Al-Kāfirūn and An-Naṣr: Applied Madd, Idghām, Ghunnah and Waqf

• A throat letter precedes it
• It bears fatḥah and is moving
• Mīm follows it
• The word contains tanwīn