Eating old cooked meat as long as it's been refrigerated and does not smell bad or have mold on it is okay.
Just because cooked meat is old, it does not necessarily mean that the old cooked meat is unsafe to eat.
Cooked meat is usually good in the refrigerator for up to 7 days before the cooked meat spoils and should be thrown out.
The cooked meat lasts longer in the freezer than in the refrigerator because the freezer temperatures prevents bacteria from growing on the meat.
That's why raw meat lasts longer in the freezer than it does in the refrigerator because the freezer is too cold for the bacteria to grow.
When cooked or raw meat is in the freezer it lasts for up to a year or more.
The worst that would happen if you do eat bad old cooked meat is that you get a stomach ache and possibly slight food poisoning but you're unlikely to get deathly sick.
However if in doubt it's best to throw the old meat out and not risk your health.