My son is overseas right now is there a way for him to receive updates without extra charges?
HE can't get carrier updates at all. Not until he is back on Verizon network. He can update applications over wifi, when he can find a connection.
Some phones can receive, download and install system updates over the wifi only connection without being connected to the Verizon Wireless network. There is no guarantee that the DROID Turbo is one of those models until the customer tries to update over wifi only.
The only reason I suggest it is possible is I have updated one of my devices when it was not active on a line, without a SIM card and on airplane mode over a wifi only connection in the USA.