Morgan is the definition of a niche market, and I'd offer that they are really the only one in their niche.
There are other 3-wheelers, cheaper, faster, perhaps "better" and more modern. Just as there are cheaper, faster, and more "real car" sports cars. In fact, in any objective comparison, a Morgan would loose. A $100k car with side curtains? Really?
But there continue to be a demand for them, thank goodness! I seriously doubt there is much market expansion to be had, but I could see the Plus 6 as successfully blending the modern with the traditional in a very unique way.
Just one ask - please bring on a manual gearbox, and sales in the US. Even so, I can't see replacing my C7 Corvette convertible daily driver with a Plus 6 that costs twice as much. And I can't see replacing my M3W with anything - period.
When my wife was looking at a new plus 8 (2004) she once said, well maybe I should just get a Miata...... I said that in 10 years you will throw it away.... get what you want for the rest of your life