I think it's for the more casual audiences who, if given a choice, would unthinkingly demand to see the seasons in order, then be appalled that (1.) the William Hartnell episodes are a very acquired taste and (2.) they can't binge the entire series in order because so many episodes from the first 6 seasons are missing. I'm actually kinda surprised that they've been jumping around as much as they have. I figured that they'd just do all 7 Tom Baker seasons in order, then all 3 Peter Davison seasons, then probably jump around between Jon Pertwee, Colin Baker, & Sylvester McCoy. A few questions I have about upcoming blu-rays: Will "The Twin Dilemma" be included on a Season 21 set with Peter Davison's final stories or will it be moved to Season 22 with the rest of the Colin Baker stuff? Will they take another crack at recolorizing "Invasion of the Dinosaurs, Part 1"? The results from using chroma dot color recovery on the DVD were far from satisfying. Meanwhile, Babelcolour's work on recolorizing "The Mind of Evil, Part 1" from scratch was very impressive. I'd suggest getting him to work on that. "Talons" isn't my favorite, either of the Tom Baker years ("City of Death") or Season 14 ("The Hand of Fear"). However, it is absolutely top tier Tom Baker stuff. Sure, the casting of Li H'Sen Chang is unfortunate but I don't think anyone is really watching the story for that character. It's all about Leela and Jago & Litefoot!
Hartnell's era is acquired, for some - I took to it instantly and that was decades after Hartnell left the show... but in 2010 anything prior to 1990 would be for many. But not all. I'll concede that trying to watch material from 1940 is not easy, much less than "A Trip to the Moon" show from 1902 (and its 1897 predecessor, as I recall seeing on youtube. Kids today would only use it as a cheap alternative to Unisom sleeping pills...) And, yeah, even with animations the first six series won't be complete. Some stories won't be animated due to relative complexity. They did similarly to the DVD releases - 1 or 2 stories per Doctor in one year and the stories were random, not based on popularity. The US releases are generally from the same masters as the UK ones, so it will be interesting to see when they get to seasons 21 and 22... For "Dinosaurs" I'd reckon they would colorize it, matching source material for accuracy. Or by then chromadot recovery will have improved, but if the source material lacks the definition for each RGB phosphor luminescence level captured... Season 14 is one of the all-time greats and it's got the wonderfulness of Leela in it as well. Yay, deadly robots - which seem cliche except these robots are entirely compelling. Or should I say, Taren Capeling? Didn't they do the same thing for the ostensibly Tibetan character Cho Je in "Planet of the Spiders" as they had Li H'Sen Chang? After casting Pik-Sen Lim as Chin Lee in Mind of evil (didn't she turn out to be a goodie and not a baddie? I'll have to rewatch!) and even forgiving Marco Polo since they had been able to get Zienia Merton (Burmese, emigrated to the UK) and that helped add some authenticity. Times have changed so much for the better since then... If nothing else, at least "Four to Doomsday" was the first story to consciously do proper casting based on ethnicity. Bert Kwouk deserved dialogue better than that of a rough draft, but the same can be said for any actor in that story. Which is surprisingly fun to watch but it's got its moments of "bleh" too...
Oh, I'm a huge Hartnell fan. But I had to work my way up to that. When I first started watching the show back in 2003 or 2004, I started with Tom Baker and found the pacing of his era to be a tough slog in places. The earlier stuff was even worse. But once I got used to the peculiar pacing of classic Doctor Who, my favorite eras of the show are the early Hartnell stuff and anything with Troughton & Jamie. IIRC, they were able to capture the red & green chroma dot information but the blue had been filtered out when the telecine print was made and can't be recovered. As a result, the colorized version on the DVD has a very sickly look to it.