Yeah, it is more of a worry than others. My neighbors driveshaft would be of more concern off road. But, he doesn't have 4wd and the transfer case adds about 18" to the transmission length so it'd be more of an angle than this.
But that still doesn't change the fact that if a 'bump' was coming up to the back wheels that was more than half the wheel height that it'd nail the driveshaft, they don't turn the differential to accept the driveshaft at a new angle with the two piece. The 4x4 tundra, according to toyota, is a 1 piece.
That is the 4x4 btw and it looks to sit lower than the F150 above.