The folks at Rocky Mountain NP teamed up with Toilet Tech and then brought in University of Colorado Denver’s College of Architecture and Planning to create an innovative solution to human waste management on the Long's Peak trail. They've managed to keep multiple toilets working there successfully for decades, and this is their latest system. This trail is very similar to Whitney in terms of heavy usage, high elevation, and harsh weather (more so than SoCal). The result - the annual "Small Projects Award" from the American Institute of Architects.
Simplicity is the key. This toilet is located at higher elevation (12,760 ft) than the one that was removed from Trail Camp, so there's no technical reason why it can't be done on Whitney.
This doesn't mean you can't use a wag bag even if there are toilets, that's how its done at almost every high-use remote trail out there. Whitney is the unique special case experiment where wag bags are the only option, no toilets. And Whitney is the one with the most complaints, by far.
Congratulations to everyone involved in this innovative project, you're advancing effective solutions to a very challenging problem! Long's Peak Toilet Wins AIA Award