No, the roomettes fill the role.
An all roomette viewliner would have 16 roomettes plus a H room. That would have the capacity of 34 beds.
The classic slumber coach had 36 or 40 beds but no H room. With an H room the capacity would be similar to an all roomette viewliner. So just build an all roomette viewliner if the demand is there.
I don’t know if demand is there for more roomettes at Amtrak’s current pricing. I do know that there is unmet demand for the following:
1. A small number of very high-end rooms. If Iowa Pacific could fill a few attached to the City of New Orleans, Amtrak could on its long-distance trains.
2. “Cabins for One,” as Via and other railroads offer them, and I would pay for one.
3. A budget coach accommodation (surely at least some bus passengers would go for something like a commuter coach attached to Amtrak trains, at a lower price than regular coach.
Given railroads’ large overhead, and how close Amtrak has come to breaking even with a load factor of about 60%, it’s clear that one path to profitability is simply filling more seats and rooms. The marginal cost of each is low.
Airlines differentiate on pricing and product between a wide variety of customers, and niche segmentation helps them maximize revenues. Amtrak should do the same.
My American Airlines app shows 7 tickets already booked for my travel for the next 6 weeks. Amtrak could have gotten each of those trips if it simply offered a product that better matched my needs, instead of offering either a product that is too far below (coach) or too far above (roomette, priced for 2 people even though I’m traveling solo).