"But the point remains: Nvidia intends to roll out new GPUs faster than ever."
What are you talking about...? Early on Nvidia used to release a new GPU family every year; Riva 128 (1997), TNT (1998), TNT2 & Geforce (1999), Geforce2 (2000), Geforce3 (2001), etc.
Sure there were a few misses along the way, but Nvidia are one of the few companies that consistently pushed a yearly release cycle back in the day, even if not a new architecture at least you'd get an improved offering in some way be it process shrink or architectural tweaks (e.g. G80 > G92 which improved texture processing even though main core architecture stayed more or less the same).
Intel's Tick-Tock methodology wasn't something revolutionary. But due to slower improvements in manufacturing over time and different market conditions, neither really have stuck to the same release schedules.
Also, let's be realistic - the faster they keep releasing new chips the less time they have to recoup costs bringing it to market, and lowering the product tier for existing chips (which may not get a lot cheaper to make) over time to sell alongside the new top tier chip may not stay sustainable over time.
Much like the early 3D accelerator days, whilst there are still some new developments to take advantage of and boost performance I expect the development rate will slow years quicker than it did for 3D graphics.