[bazar01]

It depends on your front tires wear condition before you pull out the control arms and also on the condition of the ball joints,
bushings and tie rod assemblies when the last front wheel alignment was done.
If the ball joints, bushings and tie rod assemblies were all good when the last alignment was done,
you might get it back to it's original alignment settings when you install the rebuilt control arms.
But that's assuming the control arm bushings and tie rod assemblies are all still good and tight.
Otherwise, it is still best practice to get an alignment after replacing the control arms, ball joints,
bushings or tie rod assemblies that way you'll know if there are other issues that need to be corrected before the alignment is done.
Normally alignment shops will not proceed with alignment if some suspension components need replacements.
It boils down to warranty and liability as Britwrench had mentioned.