I hope the Prankster Dark types can learn this... (and hopefully non dark-type Pranksters too)
No. They don't need any more ammunition to troll with.
Topsy turvy with prankster would be a incredible asset that would turn a crap pokemon into a good pokemon. Imagine a moxie Salamence that has used 3 dragon dances and just torn your Dragonite into bloody chunks and you have nothing with ice shard. Suddenly PRANKSTER INKAY shows up and makes Salamence go from Sonic the hedgehog and the Incredible Hulk's bastard child to a limbless infant.