>>41769816gim·mick
/ˈɡimik/
noun
a trick or device intended to attract attention, publicity, or business.
Megas, z-moves, and dynamaxing were all individually advertised in their own videos before their respective games released and further tied into the plot/conflicts of said games. This matches the definition of gimmick word for word.
You cannot say the same for Drizzle Politoed in Gen 5. Stop being fucking retarded.