I was going to chime in with something similar, but much less informed than this. There is likely aging, and then there is aging, even after the initial aging. So maybe cracking a tin changes things, but does not "stop aging".You are comparing apples to oranges.
This thread is about aging tinned tobacco which is totally different than aging whole leaf. The tobacco you get in a tin has already been aged a minimum of 2 years before being purchased by the manufacturer. It is then processed( with sauces) in to pipe tobacco. It is these sauces that are affecting the aging of the tinned tobacco.
Jitterbugdude... Is aging in a tin enzymatic like the initial aging, or bacteria (aerobic or anaerobic), or both?