This was my thought too.I have a lot of friends that work there and Disney executives have been spending a good amount of time at Blue Sky recently. Disney is telling them they want them to keep making theatrical movies but they all expect a decent amount of their work to shift to Disney+.
Disney is essentially building a "third pillar" beyond television and theatrical films.
Some of the redundancies (like Blue Sky) seem most poised for Disney+ integration instead.
Pixar/WDAS are terribly expensive producers of animated content. As much as we'd all like it, I doubt they'd spend 100+ million on a Disney+ original. Really Pixar Vancouver would have been better suited and probably would have survived if Disney+ was on the docket years ago.