Yeah man i said the same thing last year 
It’s a pretty neat trick.
Heres a thread i started and a plant i re-vegged.
She is absolutely huge now 
I will be updating the thread soon as im going to flower her again and I will scrog her and fill a 4x6 tent with only her…
She was a tiny bonsai with first harvest, she is now 10 times the size she was with first flower.
But this thread walks you through how to do it.
And it only works with photo period plant’s from my experience and understanding of how and why it’s possible and autoflowers just do not fit the bill.
Since autoflowers are not dependent on environmental conditions to trigger flowering, I don’t see a mechanism to be able to manipulate it 
I feel like if anyone has gotten an auto flower to re-veg, then it wasn’t a 100% autoflower to begin with 
.
I could be wrong but I’d be very surprised
Re-veging is trigged by takeing it from a 12/12 light schedule straight to a 24 hours a day light for a couple weeks…
Since lighting hours do not effect a true autoflower, it would have no effect on them.