Re: CF-53 Toughbook....
Have one of those here too… without the cellular option.
There are a couple of Thinkpads that embed cellular capabilities too that are about 4 years old now. So the idea has been around a while.
Not sure if the "novel" aspect of Apple's filing is the ability to make phone calls or if it's going to be just purely for data, in which case I think there's reasonable grounds for patent invalidation due to prior art.