>>50831870I think GF is just ramping down the number of new type combos introduced each gen.
Gen 5 introduced 19, 6 introduced 16, 7 introduced 13, and 8 only introduced 8.
Right now, there are only 16 unused type combos.17 if you don't count Dragon/Fairy because Mega Altaria is gone forever.
New typings are a selling point and increase hype. Impidimp being a good example.
I think there'll keep being fewer and fewer new typings introduced each gen, just so GF doesn't run out for a while.