Since early last year (2016), Vizio, a world leader in consumer television/video display systems, has been phasing out the production of television sets with tuners and moving toward the production video display systems without tuners.
Tunerless displays, is the legal term, in order to bypass the federal government's requirement that all TVs have a tuner capable of tuning in local over the air television channels. Removing the capability of an RF connection qualifies the devices as displays, rather than television sets. Basically, all displays that are 4K/UHD capable and are equiped with Vizio's smartcast system are display units, or tunerless TVs.
Complete imformation isn't quite transparent, however, keeping in mind the difference between the terms "TV" and "Display", it appears that the "M" series and the "P" series are all smartcast capable so, are displays and are tunerless. The 32" version of the new Vizio "E" series is a smart TV, but all units of a larger size (43" and up) are smart displays and come with Smartcast. All sizes of the Vizio "D" series are smart TVs, without Smartcast, Some models, but not all, are available with 4K/UHD. I think sales will drive Vizio's decision as to whether to keep the series "D" sets on the market, or to convert them to displays.
As far as the other major manufacturers are concerned, I don't see a move toward specifically digital displays, but a few of them have separated the tuner from the video display unit either as a separate box or as a part of the stand. I am certain manufactuers like LG, Samsung, Sony and other major manufacturers are either, at this time, or soon will be installing both ATSC 1.0 and ATSC 3.0 tuners in their TV sets. However, I haven't been able to find a reference to any dongle or converter box available, as yet, as a separate or stand alone device. My IEEE source material has very little information, also. That is about the availability of products related to the ATSC 3.0 standard for the consumer. I get a lot of technical information through the IEEE, on ATSC 3.0, as far as physical structure is concerned, just very little about products available to the consumer.
Personally, I don't like being tethered to a cable or a dish, for television, when I can pick up a perfectly good signal right in my living room. Looking ahead, though, I can forsee either the requirement of a separate tuner/converter or replacement of my TV set. I am praying for the former.
What I really foresee, is a ton of confusion, in the broadcast markets, in that not all stations will convert at the same time, leaving the consumers with some stations broadasting with ATSC 3.0 and some with ATSC 1.0 and a need be able to receive both with the same equipment. I have faith that the industry will come through with the right answers, when needed. It might be too much to expect, though, for all the local broadcasters coordinate with each other when any conversions are decided upon, but it would be nice.