Apple will display Holiday Hours as "Special Hours" for a given 7-day timeframe if we are within 4 days (or less) of the given holiday hour.
Data updates made in Yext will take up to a week to display on Apple Maps. This includes both the addition and removal of Holiday Hours. Apple allows a maximum of 50 holiday hour entries.
This means that Apple is not going to display the "Special hours" for the whole year that you already added in Yext - this is the Publisher's behavior/limitation when it comes to displaying the "special hours."