There are two problems that I would expect from rolling un-aged leaf into cigars, then allowing them to age.
First, leaf loses 10% or more of its dry weight (solids) during the aging or kilning process. So a properly rolled cigar of unfinished leaf would likely end up too loosely packed after aging.
Second, the components (wrapper, binder, filler) of a rolled cigar held in a specific environment tend to take in and give up moisture at different rates. The wrapper will always dry more quickly than the rest, risking spontaneous splitting. With the filler, the open foot always dries more rapidly than the closed head. Although making humidity changes very gradually can minimize this risk, it's still a tricky business.
These are just my thoughts. Since it's just as easy to do the rolling once the leaf is properly aged or kilned, I'm not inclined to risk the time and effort to do it the other way around.
Bob