I've heard of it but assuming people buy tobacco blends they like, I don't know why anyone would do it.

Furthermore, the way I look at it, it's not really 'aging' but more like stoving the entire mixture at once so I doubt you'd get an accurate idea of what the mixture would taste like in 10/15 years... if that was your motivation anyway.

Digressing away down a rabbit trail:
I generally avoid buying tobacco I don't like. But that being said, if I was stuck with a few tins that I just couldn't stand, I might try something drastic in a last-ditch attempt to change them into something I could stand... however, the few tobaccos I've tried that had absolutely no redeeming qualities were nasty aromatics and I doubt any amount of baking would neutralize the goop, chemical taste and bite that made them foul in the first place. Maybe +1200 degrees for an hour or two would do it - like hucking the entire tin in the burn barrel or wood stove...