The Legion did have a cartoon series that did relatively well around a decade or so ago, but to market it to a mass audience is a tough proposition, it can only succeed (in media and comicbook form) if it is reconnected to the Superman mythos and has a young Clark Kent spearheading it.
Geoff Johns took a creditable stab at it back in the aftermath of Infinite Crisis, reintroducing Clark Kent's Superboy career to the mythos and taking a very strong hand in resurrecting the Legion with Gary Frank then George Perez. But it all led to nothing. The Flashpoint reboot hit in 2011 and it was all washed away, all of it. However enjoyable you might have found Doomsday Clock's conclusion there is nothing to say it exists in-canon. I certainly don't see Brian Bendis paying it any attention as he tends to go his own way as a creator, and by this point when considering DCs treatment of the Legion, and its long retirement and veto on Superboy/Clark Kent, It is hard to see a way forward for the Legion.
This current revamp joins the three that Geoff Johns collated back in 'Legion of 3 Worlds' to make it four Worlds. Four Legions. Is there any wonder then the team lacks appeal to the audience....
I watched it some but not enough to get a feeling on its quality. It had Superman when he was all but Superboy in name. It brought in another Superboy clone at one point. I should watch it all especially since I have it here someplace.
Looking at what Geoff Johns and others at D.C. have said about Doomsday Clock they give varying answers. Johns says it is a stand alone while others claim it has great ramifications for the entire D.C.-like we haven't heard that before. I suspect Johns view on the matter is the correct one since he created and wrote the series. More of a different way to see the overall meta-multiverse rather than a direct change of continuity. There will be a sequel but for Odin's sake don't let it be a prequel!