I was just on the Dillon Precision forum and was surprised to read that they actually recommend tumbling loaded ammo for 10-15 min in plain cobb to remove the case lube. I know some say yes and some say no , but I was under the impresson that the general feeling was no no ..
You obviously know the arguments and "logic" (such as it is) both ways. Those who live in fear of unseen demons won't be persuaded otherwise and, personally, I don't care what they are afraid of but their unfounded fears won't change anything in my shop.
The tumbling loaded ammunition question is right up there with shooting 5.56 MM in a .223 chamber. A lot of people say not to do it. Yet no one can ever provide a link showing a weapon that was damaged from doing either. I don't do it because I tumble after resizing and depriming. It adds a step, but I don't like handling cases sticky with lube. With that said it isn't going to, "rub the coating off the powder" to tumble for the 10 minutes or so it would take to remove the lube after loading. It's most likely less bumping around than a lot of this 40 year old surplus ammunition has seen.