Alolan Bidoof asks:

If it were up to you, what would you give to the inevitable 1000th pokemon to commemorate it?

Hmm.  I suppose it feels as if there should be something special about #1000, doesn’t there?  You know, one thing you could do would be to have a contest to let a fan design a Pokémon – obviously with some tidying up by Game Freak’s design team in between the winning entry and the finished game.  I think if I were in that position I might restrict the contest to residents of Japan, just to keep the scale manageable and make it easier to get some back-and-forth between the winner and Game Freak over how the design would be interpreted for the final game (but you could have a bunch of other regional contests in the rest of East Asia, Europe, North America and so on for the #980, #990, #1010, etc. slots).  That, to me, would feel more special than any gimmick that could be added to the design of the Pokémon itself.