The "brand" is obviously valuable... for cigarettes, not pipe blends. So, they'll keep the brand. If the price is right I'd bet the investors would sell in a minute. The right price will be predicated on the cigarettes, not the blends. Luxury cigarettes return on investment (Nat Sherman sale is a case in point). There simply are not enough of us, pipe smokers, toinduce investors to keep making the blends. The moneys are in cigarettes, a growing market, lots of demand worldwide.
Investors invest only when there is an expectation of a reasonable return on such. If Dunhill had been a small company, only making blends for pipes, showing only sufficient profit to put a car in the garage and food on the table for the owners, there would have been little interest from serious investors and the brand would have been safe, unattractive as an investment. The pipe tobacco blending business simply has too little profit to be attractive to serious (read big money) investors.
If there were good profits to be reaped... we wouldn't be having this discussion.
Not sure why a "black market" would develop simply to provide product for a relative handful of consumers. Even black marketeers consider profit to be made from illegal operations. Again, it's profit motive which drives the business, not the desires of a tiny market. Now making ersatz tins and loading them up with some Lane blend, to be sold at a premium? Might be some profit there. New smokers wouldn't know the difference, some of us would decry the fraud and few would care.
The owners of the Dunhill name will guard the name. The very idea of creating yet another Dunhill brand, which would create even more confusion than we see on this thread, would not be in the best interests of the owners. Dunhill, as a marque, has value. The blends? Not so much.