Yep, I have some 15+ yr old servos that are still flying. (JR NES-505's).

The one to watch out for is old Airtronics. Their old connector had the wires in a different order from everyone else. You can get adapter cords, or just re-wire the connector yourself, then they work just fine.

The signal standard between the RX and the servo hasn't changed at all in many years.