Walt Disney had nothing to do with Daniel Boone. The program was produced by 20th Century Fox and Fess Parker's production company. Fess didn't get much out of all the money Davy Crockett generated and Daniel Boone was his attempt to cash in. The PBS show got this fact wrong. Apparently, the producers weren't big on research.
Yes, they barely mentioned the early TV Westerns, particularly The Lone Ranger. It was one of the first - if not the first - western filmed for television and it was the first ABC show to break into the top 10.
Only one brief clip of the Cisco Kid, which was not be considered PC today but was noted at the time for great production values and for being one of the first shows filmed in color.
Many of their choices of which shows to include and which not include were questionable and based on: Which shows they could clips from and which actors they could get to talk about them (they seem to be using a lot of the same actors each week). In this regard, the "pioneers" show was reminiscent of Biography. And the other factor seemed to be political correctness because the show seemed to focus on which shows gave significant roles to minorities and to reflect modern standards of ethnic relations. It might have been instructive to show some depictions which would not be acceptable today.
I especially take issue with the show's laudatory treatment of Gunsmoke, which was a bastardization of the radio show. Gunsmoke was completely unrealistic and does not hold up well. Ignored was Have Gun Will Travel, which does hold up well thanks to excellent writing (by Gene Roddenberry and Bruce Geller, among others) and Richard Boone's performance as Paladin. No mention of Rawhide (in which Clint Eastwood was second lead) and just cursory mention of Wagon Train, which brought some of the great movie stars of the era to the small screen (probably because they were clients of MCA, which produced the show).
They doted on The Rifleman, claiming it was "created by" Sam Peckinpah (he actually wrote and directed a few episodes), and then spent more time talking about his movies than his TV westerns.
Bottom line: A very sloppy, superficial job. Not ready for cable, let alone not ready for prime-time. It will probably become a pledge drive staple. Let's see how much they get wrong next week.