Supro, Harmony, Magnatone, and any other formerly defunct, revival brands will likely fall if tubes are no longer produced. The only reason these revival brands even work out is because of the history they had. Without any tubes, they will not have anything resembling their heritage, and they will just be another stamp on the side of an over-engineered CE, and RoHS compliant OEM circuit made in a second or third world country.
Carr, Dr. Z, and few others are truly independent companies that DO NOT play much in SS circuitry. I don't think they will delve much into trying to break into printed circuit boards and transistors. Toneking was once all turret board design, but like many have sold out and in order to meet a world market, have gone to PCB, with marketing and distribution from a third party. What's the point in trying to reinvent the wheel of a format that is still not perceived well. If you could choose between a Fender Tonemaster, or a Fender Deluxe Reverb, which are you more likely to choose? I would will a good bet MOST would go DR. If you had to choose between a Freidman BE-100 or an Ibanez Toneblaster ( a damn fine amp ) I bet 99% would go Freidman BE-100. The list goes on; tube amps are the most sought after. Without tubes, you are just another name in a VERY BIG HAT.