In Gen 5 games Assist does not call up Dive or Bounce (or, I presume, other 2-turn moves) when I've heard that it does in the past (Prankster-Assist-Fly with a Lagging Tail, for example, being a strategy). Not that this is brilliant evidence, but this is a thread that talks about it.
http://nuggetbridge.com/forums/topic/910-diving-purrloin-and-liepard/
Anyway I tried it out on the sim and it didn't work. Purrloin tries to Assist on Turn 4 and it fails, while Ludicolo shows it knows Dive on Turn 18 and Lopunny uses Bounce later.
http://pokemonshowdown.com/replay/gen5ru-69177846
I've heard that Assist was changed in Gen 6 to no longer pick up 2-turn moves, but this was a Gen 5 battle, and if I understand correctly it shouldn't be affected by the change in Gen 6.
Anyway I really apologize if this has already been addressed. I did my best to search thoroughly before posting.