Should a sous-vide-cooked meat be frozen then reheated?
This shouldn't be a problem. What I recommend is to go in this order:


Don't pre-salt the food, other seasonings are fine but anything with a high sodium content should be left out
Cook to your desired temp (and I would recommend pasteurizing since it's not a direct serve situation
Pull food from bath and plunge immediately into an ice bath filled about half and half with cold water and ice to rapidly drop the temp of the food
Once chilled, put in freezer to store, leave them directly in the bag your cooking with. If your using ziplocks I would suggest wrapping them in plastic wrap and then putting them back in the ziplock before freezing.
When it's time to reheat, repeat your sous vide process from the initial cook. It will take the same amount of time it initially took to bring the core up to temp + the time it will take to unthaw the food in the bath. Reheating direct from frozen is your best bet for quality. 
Post-sear the food and add salt at that point. Adding salt at this point will prevent the food from taking on a cured texture when it is frozen and held for a period of time. 
Enjoy!