Practically speaking, it would be difficult to verify that every datum in the expired GPS database relevant to your filed flight was current in order to file /G. I suspect the FAA would take a dim view of any accident resulting from using expired data. Using the VOR/ILS capability of a GPS/NAV/COM is no problem as you can tune navaids by frequency, not by name. But in this case you will need current charts in order to do that. VOR stations DO CHANGE, by the way. They can be decommissioned (as in Lake Henry, which went from a VOR to a GPS waypoint) or renamed (as in Binghamton, BGM which was renamed to CFB so as not to conflict with the airport identifier). It doesn't happen often, but it happens. Intersection names change, too. If you are going to fly /G IFR, spring for a current database. Unfortunately, Garmin's databases are now much more cost competitive than Jeppesen. I dumped Jepp for my GNS430 when Garmin's databases came out and were about 33-50% cheaper.