The "15" thing in that story is about non-transforming figurines. Not 15 generations toys, not 30 thrilling toys or an accurate count of the movie cast or anything like that.

Paladone Products Transformers Figurine Collection will make its debut at Gallery 145 with 30th Anniversary and Transformers: Age Of Extinction figurines. With a total of 30 characters, the line is separated with 15 characters each for 30th Anniversary and Transformers 4