And hasn't there been multiple sources say that at least one of the films in development are traditional?
No. I'm pretty sure there weren't. If you are referring to Mort, that was canceled a while ago and if you are referring to the proposed Mickey Mouse full-length feature, that was merely a pitch (out of many) that Burny Mattinson was working on which at the time had yet to present.
Even if Lasseter liked the first pitch, and gave the OK to work on the pitch some more, the project would be on spec. development (i.e. presenting another more detailed pitch, getting feedback, and re-presenting it, and so forth). After this process if the story seems to be working out, it will get greenlit for development (where the process of making the film actually begins: a bigger team working on the project, story meetings, storyboarding, concept art, research etc).
If the project had been greenlit for development, something would have been leaked by now so I'm inclined to believe that it hasn't; at least not yet. There is also the possibility that the project was rejected, not passing the pitching stage or perhaps it got turned into a short. Anything is possible.
Currently, the only projects that have been confirmed at being in development are:
Chris Williams' "King of the Elves"
Dean Wellins' Untitled Film
Greno's & Howard's Untitled Film
Chris Buck's Untitled Film
Also, a full production has begun for "Reboot Ralph", "Prep and Landing: Naughty vs. Nice", a "Tangled" short, and 2 other shorts.