Well, I meant "added in" as in "added to the game as a whole." That is, by the time the postmoogle quests and Thancred's disaster were coded, written, and translated, I think the Loc team had already realized their mistakes. I admit my earlier phrasing was unclear, though.
As for Thancred (and Longhaft) in general I think it generally comes down to the difference between things happening to NPCs versus to the PC. You're right that both these NPCs have reputations as a womanizer or a walking double entendre, but neither of them are really directed at the player character. I mean, most people laugh off Thancred's passes, but some people get upset at Longhaft's shtick. And the response to the Horse year Heavensturn event was...mixed. If their goal with the 2.0 quests was to minimize the people offended by Haurchefant's character, I can totally understand why they made the changes (again, went too far, though).