OK, I'll take a shot at what the OP is hinting at:
Most 4X4 Tacomas, from 2005-2015, had a bad vibration in the driveline that was blamed on the 2-piece driveshaft. The vibration was insidious, having multiple symptoms. It usually manifested itself under acceleration from a stop, but could also vibrate at speeds ranging from 35-50 mph. It was a really bad thing that Toyota never fixed, or even admitted to. It was left to the poor owner to fix.
The BEST fix was to replace that 2-piece driveshaft with a custom-built 1-piece driveshaft, but that created clearance problems/issues when off-roading and cost multiple hundreds of dollars. Other mitigation techniques were focused on using spacers of various thicknesses between the center bearing mount (for the driveshaft) and the frame. Some after-market companies (Old Man Emu?) even made special spacers specifically for this application (what I used on our 2006 Taco). The spacers lessened the vibration, but never completely eliminated it.
So, what I'm HOPING the OP was referring to is that Toyota--finally--eliminated the vibration (without ever admitting it was a problem). How he would know this is a mystery. But, if it is gone, that would be a wonderful thing!