Is it possible cannabis is in the middle of evolving dioecy from monoecy and is not finished the process yet?
I'd agree in principle that we could observe this is happening in some populations, (I think we may be closer to androdioecy in some landrace S.E. Asian Sativas) although it's important to point out that obviously evolution follows no plan, it's dynamic and ever shifting towards what provides the most apparent benefit in various local circumstances.