Yeah, they're left handed on the 2000s, too. The problem is that torx bolt (on the Bonneville'*) that just doesn't make things as easy as the regular head. My son'* '99 GP, and my future son-in-law'* 00 GP that I'm working on now both have the left handed thread on the tensioner, but it'* a standard head. This is on the tensioner only.
Yes the tensioning setup pictured with basically runs 96+ on the series 2 motors requires a left hand threaded bolt. You need to move it counterclockwise to remove tension and the belt. Therefore the tightening of the bolt has to occur in the opposite direction without some other fail safe locking type mechanism to keep the bolt from loosening.