The last time they weren't able to use a concept for a toy (Animated Constructicons/Devastator) was because of their usage in the upcoming TF2 movie. (or perhaps Hasbro don't want Grimlock tied to their offshoot PCC line, if they have grander plans for it later)
The drone limbs were the same spring-loaded gimmick, so don't expect too much from their limb-forms. Their dino-modes seemed more generic than homage, to be able to form limbs without too much dino-kibble getting in the way. Quite a few colours too - don't think 'gen1 grey'.