Some early traction control systems in cars used the same double-throttle setup. I presume this is just the simplest way to slap a feature like that on as an afterthought.
The R1 didn't so much as accelerate as it teleported at wide throttle angles in 1st gear, combined with no squishy rubber isolation bits adding mechanical latency to the system. The phenomenon was very apparent and nerve-wracking in the right conditions.
But things like this are certainly just one more reason that I do not ride liter bikes.
I've never heard of a car with a second throttle for traction control. You might be confusing variable intake geometry vanes.
See: http://www.eatsleeptinker.com/2014/06/02/asc-throttle-body-d...
But I should be careful what I wish for. Current BEVs have many user-hostile clown-car features.
The excessively (and negatively) complicated addons described in the thread are not inherent to ICE cars. Take any car from 80s or 90s and the behavior is predictable and simple. It's only into the 00s that manufacturers started making things too complex and as a consequence, fragile and unpredictable.