Anyone has experience on when EVA might clear a waitlist for a *A redemption ticket?

I booked my parents on a J class *A redemption ticket using KF miles for departure mid Dec, more than 3 months out. One sector KIX-TPE is operated by EVA and my dad is waitlisted to be on the same flight as my mom. Am worried whether the waitlist will clear as Dec is a holiday season and how long should I wait before I explore other routings to book for KIX-TPE.

Thanks in advance!