For example, Snorlax stood up over 6 generations as displayed below (middle sprites are both Gen3)
Jumpluff also jumps or floats, as seen below.
Is this intentional? Or just a coincidence for these two?
Bish, don't be makin' fun of Snorlax.
There is no way to tell. There might be some Pokemon who look they are doing actions like Snorlax, but it doesn't seem like there are any that look as if they are going through the motions.
Until Pokemaster takes us on a field trip to go visit Game Freak, we'll never know.
But I am looking through some of them, so I might update this, as some have come pretty close to making sense. :0
EDIT: This one doesn't work out in order of generations or games, but look:
Its like he's jumping :OOOOOOOOOOO!
Mewtwo awakens and he uses that attack from SSBM!
Or you can look at it like power is surging through Mewtwo :l
Anyway, as you can see, these actions are all obscure so either it was special to GF or it was a coincidence. I still think the Jolteon one works out though. :)