Is there a certain time frame or other ways to predict when a Subeautique set will retire?

Nope. You kind of just have to wait until staff announces retirements, but they always retire the 2-4 oldest ones first, which I believe are currently Siren Pull the Trigger, Rainyday Ethereal, Cece Kat, Kore Woodland Walk, and RoQ Candy 2Scare

OK, that's helpful to know. thanks