First is a callsheet for the movie which clearly mentions great many people needed to perform "Dinobot Stunts." This seems pretty clear cut to me; you can check out the scan over at Seibertron.
The second doc is an internal Toys R Us sales sheet detailing Hasbro's 2014 lines, which calls the movie toyline "Dinobot-themed."
Would Hasbro release Dinobot toys for a non-Dinobot-starring movie? Possibly, but not at all likely. And I sincerely doubt the line could be described as "Dinobot-themed" if there was, say, only one transforming robot-dinosaur making his on-screen debut. Also, that seems like a lot of Dinosaur Stunt manpower on the callsheet if there's only one Dinobot. Just sayin'.
Anyways, this is much stronger evidence than the last bit of "proof" that TF4 would include the Dinobots, which is that the TF4 logo on this crewperson's hat has claw marks in it: