I can't imagine how it would be beneficial.
Is there much difference between doing that and actually harvesting a few days early?
Whether I cut the stem and prevent the roots from supplying the rest of the plant, or stop supplying the roots...its effectively the same thing, right? The plant will will and start drying put. So you're basicslly asking "would there be any benefit to harvesting a day or two early". And that's obviously a no.