Yes. If the OP hadn't already pulled them, I would have said to measure the OD at the bullet base location before and after pulling (measuring all around and averaging the results, as the unoccupied case necks can be slightly oval in cross-section). If the difference were over 0.001", then I'd have said it will probably serve well just to use it as-is. But if it were less than that, I would resize the necks. Now we can't know, so sizing the necks seems like a reasonable preemptive measure.
What is affected by this is the pressure at the moment the case neck lets go of the bullet. How high pressure has gotten at that point affects how quickly pressure goes on to build to its peak after the bullet gets into the rifling. If the peak is delayed, it is usually a little lower and barrel time gets longer, so if the load were a carefully tuned load it could now be off and you could see groups open up, even if the loads behaved consistently. But as MG points out, that may not happen, either.
I have, BTW, pulled bullets from military ammo and seated others without sizing the neck, a la Mexican Match, and it worked well, taking a 3 moa load down to about half that. However, military cases held their bullets with pitch sealant, plus the lot of Sierra MatchKing bullets we had were measuring half a thousandth wider than the original bullets, IIRC. So you have to adapt to the circumstances.