Rotor replacement

Sure.
I professionally wrenched for a living for about 30 years.
Back in the day it was standard practice to machine, drums, rotors, when doing a brake job.
Now a days shops don't even have a brake lathe anymore, as modern cars have drums, and rotors, that you just replace.
Throw a way parts.
Remove and replace.
A local mechanic/shop teacher told me that because the hub and new rotor are two pieces bound together I will have to get the new rotors cut to make sure that they are aligned (in plane) with the hub. Otherwise they could be too much runout and I'll get vibrating. What do you think about this.