I'm with Jason on this one... Resistor drift is a non-issue for modern electronics and should easily expect a ~20+ year lifespan unless there's some serious abuse involved.
Drift Calculation for Thin Film Resistors
There's much greater precision required in other applications (such as automotive/aerospace applications) and somehow the world still turns:
Resistors in aeronautics applications: Meeting the new performance requirements
I was seriously considering a MSB DAC and in one of their design videos, they state that their typical product cycle is 7 to 10 years. I can't imagine they'd expect someone to buy their $100k+ R2R DACs expecting it to sound poorly before they replace it with a new model.