Hello,
As a former Lexus Soarer owner, I'm also just returned to Lexus.
Bought a slightly older Lexus RX from Lexus. As part of the pre-delivery stuff, they also replaced the rear disks, timing belt, plugs, trans fluid etc.
I know I paid a premium, but the peace of mind for me was important.
I guess the question here maybe, were the brakes on your car safe/fit for purpose. Check your statutory rights and do a 'reasonableness' check?