One clue that this show isn't just trying to act like one long commercial for toys: the number of characters in the show. The protagonists (Team Prime) have the enormous number of *6* members in it, and number 6 was introduced late into the show's second season, some 40+ episodes in, and he was introduced in a relatively logical manner. Apparently, Hasbro didn't even initially confirm that there would be a toy line associated with the show. If true, it's nice to see a toy company that actually tries to entertain its audience before selling them the associated swag.
EDIT: It actually looks like Hasbro has two faces. One face is capable of the above, while the other still thinks only about merchandising, as this story from IGN seems to demonstrate:Hasbro CEO talks about Transformers 4 film, says it will feature new robot cast because the toys for the last film didn't sell so well.