This is a factor only if it is possible to separate a man from his universal translator. Which becomes fairly difficult if the device is actually an implant. (Not in the mechanistic sense, as a sharp knife solves most of the problems of this world and others, but in the sense of figuring out that there even exists a UT to be dug out.)
The bulkier external devices, commbadges and whatnot, might be necessary for deciphering newly encountered languages, such as Gorn, Companionese or Basics Caveman. But the implant might be programmed with already known languages, such as the Latin they speak at Merikus' planet, or the NavahoMohicanDelawareish they speak at Miramanee's.