I'm afraid I'm going to have to buck the trend here and support this imaginative neophraseologism, which was clearly coined with a view to tying up both the familiar meaning of the term (noting that if you go on vacation, you'll surely be out of pocket, from a pecuniary perspective), and its implicit subsidiary sense, viz. the opposite of 'in each other's pockets' (so, while on vacation, you'll be physically, socially and professionally separated from your colleagues, thus affording all concerned temporary respite from each other's regular claustrophobic company).