What kind of silent Yā’ and Wāw are those paused upon in words such as "al-Sa‘y (the endeavor), al-Khazy (the disgrace), al-‘Amy (the blindness), al-‘Afw (the pardon)"?

The letters waw (و) and ya (ي) are strong consonants if they are vocalized (have a diacritic mark). They are described as letters of madd (lengthening) and leen (softness/diphthong) if they are unvocalized (sakin) and preceded by a vowel that suits them (a dammah for waw and a kasrah for ya). In this case, they are called letters of madd, leen, hawaa' (air/vowel), and illah (weak/vowel). They are also described as leen if they are unvocalized and preceded by a fathah (e.g., al-bayt, 'ayn, sawf). Two unvocalized letters (sakin) do not occur together in a single word unless the second unvocalized state is temporary due to a pause. The letter ya (ي) is never unvocalized and preceded by a dammah due to the difficulty in pronunciation; rather, it transforms into a waw (و) in this situation.