While this lofty goal will be hard to reach, the transition to RNAV/GNSS/PBN as the primary method for approaches seem inevitable.
No doubt about it for IFR airports. (That leaves a whole lot of VFR airports without anything.)
And, the GNSS/GPS/RNAV IAP may be nothing more than LNAV to circling minimums and perhaps at a 90 degree angle to the runway. (example KEMT).
Make no mistake, the FAA didn't pay for WASS unless they wanted LPV to "every runway end." But, that was the high-level movers and shakers. Not those who faced with the hard realities of terrain and close-in runway environment.
Further, ILS at the principal U.S. airline airports will remain primary. As well as in the lofty ICAO world.
