Is 2.21 Coming Out __hot__ | When

If you mean — Linux kernel versions jumped from 2.6.x to 3.x, so 2.21 was never released.

If you meant — Blender 2.2x series is very old (early 2000s), and 2.21 would have been released around 2001–2002 if it existed.

Could you clarify which software or game version 2.21 refers to? That would help give a precise release date.