I am not baffled. I would say that this season's international results for Max and Jason were more or less in the same ballpark.
Max won in Salt Lake. Jason placed 2nd at Nebelhorn.
When they went head to head at Skate America, Max placed 3rd; Jason 5th.
Jason was 3rd at TEB; Max was 7th at NHK.
Even though Jason's placement at Nats won him the second Sochi spot, my interpretation of Max's assignment to Worlds is that USFS values him too (and would have been happy to give him a third Sochi spot, if only it were available).
Plus the combo of Max and Jeremy at Worlds perhaps seemed more favorable than Jason and Jeremy for attempting to earn back three spots.
Max placed 7th at Worlds last year. Jeremy's most recent showing was 8th; and his best was 5th. Jason would be an unknown quantity.
Changing the subject:
Intriguing that on the USFS website, the announcement has a question mark next to Denney/Coughlin for Worlds.