A bit like motorbikes. Basically, they should never warp, as the disc will always run true in the caliper as it isnt rigidly mounted. Or if they do warp a bit...less chance of you actually feeling it at the pedal.

But over time, both the floater bobbins and disc itself do wear....and they can rattle a bit. Or a lot.
My car is pretty noisy, and at times the rattle annoys me ! Mostly on slower roads with the window open mind.

I was considering some of the second hand discs Tony has for sale. But after speaking with the people who supplied my brakes, I think its maybe not tbe best route to take.
He has some 332x32 discs, but I'd need new bells made, and pad swept area is different too.

I'd probably just be better off buying new discs.