tbh after 100k, the warranty had ended so you are free to do what you want, and most suggest to change the ATF asap

for cars still under warranty, its totally up to you. If you want to change then you risk voiding the warranty. but if you don't and anything happens to the GB, just claim warranty

Bermaz / Mazda is not alone in this, BMW also don't provide ATF change within their service schedule.