One thing that you can be sure of is that everyones taste is different.
When I bought my new Bonnie I looked at the America and the Speadmaster also and couldn't work out what they were or what they were trying to be. The Bonneville and T100 fills a void that only a Bonnie can fill. That satisfied my taste. As for the America and the Speadmaster, for a cruiser they're too gutless. They look good and they're cheap but what part of the market are they aiming at? I couldn't work it out.
However, obviously a heck of a lot of bikers around our area could, because they are selling like hot cakes. People that can't afford a Harley but still want a cruiser from a credible mark. I think I just worked it out!
So, I have no doubt whatsoever that a 1700/ 1850/ 1920 parallel twin cruiser will also sell.
I think the guys at Triumph do their homework before investing in any new project. If it hits the showroom floor, you can garentee it WILL sell.
I just wish they brought out a new, bigger TBird. I reckon a big bore triple would sell just as well. Triples are Triumphs hallmark just as big twins are Britains hallmark. Either way would have worked.