The "sad" reaction on the previous page was a recognition that transmedia franchises are not easy to manage (despite what Di$ney thinks). Indeed, I don't think anyone really gave the notion serious thought until the 2000s -- and there isn't a single approach now, if one looks at the major ones.
Regarding the Whoniverse, the BBC feels (accurately or no) that establishing a canon policy for the Doctor and all related characters (who have their own rights under British IP law, so Pedlar/Davis Estates could greenlight a Cybermen story in which the Doctor does not appear) violates their charter as a public broadcaster, so screen adventures, comics, novels, Big Finish audios, all make one big wibbly-wobbly ball of ... well, timey-wimey stuff. (It really only gets contradictory with the Eighth Doctor's time between the 1996 TV Movie with the Pertwee Logo and "Night of the Doctor", but one can always blame Faction Paradox for that....)
Paramount takes a stricter approach to Star Trek, but even they have gone back-and-forth on the canonicity of The Animated Series. Michael and Denise Okuda, back when they worked for Paramount, snuck in as many references as they could during the Berman era as an upraised middle finger to Richard Arnold's pronouncements that it was not and could never be canon.
Star Wars developed its old sliding-scale-of-Legends-canonicity in part because Episodes I and II were not gelling well with what little had been allowed to be written about the Clone Wars era. After the 2014 acquisition, Di$ney promised a new and coherent, retcon-free approach to their New Canon. How long that actually lasted depends on whom you talk to.
The Alien franchise has had not one but two ancilliary material flushes, and the director who started it all coming back and giving us a Base Breaking return film. That said, I think that the fandom expectations, such as they were, were arguably a little stock (basically post-Vietnam mil-sci-fi and another Queen doing the eusocial-insect thing), and doing something different isn't necessarily bad.
Honestly, when it comes to ill-treated fanbases, I think Highlander wins that prize. You've got the first movie, a generally-well-regarded TV series, the increasingly-obscure anime, and, well, it's kind of all downhill from there....