Milk in a babies' bottles have been the cause of many a case of rampant dental caries. It raised the acid levels in the mouth.
Obviously for small babies, in an edentulous state, or those having a bottle with a meal, as opposed to those given a bottle to liquid graze on would be very unlikely to experience issues.
Like all things sensible quantities and frequencies are in play, when balancing the nutritional benefits of milk.
Just the idea doesn't float my boat, but then again, I'm not in the target group.