Wheels really shouldn't loose significant tension when well built. Get a good builder to build it to high, even tension without spoke windup and they should be relatively maintenance free except perhaps for some minor spot truing absent any actual trauma to the rim. If the builder uses a thread locking compound or locking nipples that adds additional insurance, particularly in uncommon cases where the wheel is overloaded (hitting potholes hard enough that some spokes go slack, but not necessarily so hard that the rim actually permanently deforms).
If you have a good sense of relative pitch, plucking spokes is absolutely a good means for checking if spokes on a side of a wheel are evenly tensioned, and is a good quick way to see if tension has changed (if the wheel is known to have had pretty even tension). It's a poor way to check absolute tension, but if your wheel builder does their job it shouldn't be yours.