See, the Tar thread was in light of new evidence (sandstorm makes SpDef increase, yada yada). This just seems out of the blue; Metagross was never considered Uber before, why should it be now?
There's no way Metagross is uber. Despite it's ability to launch insane Pursuits, Explosions, and being able to Grass Snot Swampert, it isn't threatening enough for it to jump out of OU into uber, and certainly not weak enough to be in BL