Yeah, but the thing is, 50 staff members were polled about the Pokemon and these were the results.

– My prediction is correct! I’m really happy! – 1
– My prediction missed, but I’m still glad – 13
– My prediction missed, I’m salty – 31
– I’m actually perplexed, so I can’t answer – 5

So if it was Swampert, I doubt only one person could have guessed it. And the salty remark just screams "outsider".