Well, in the movie we see Zipp actually glide after using the wind machine, so while they couldn’t go UP they could at least land without going pancake.

@Background Pony #DF3D  
Ah, no wonder they clung onto and adored the royals so much. They were the only sliver of hope left for being able to fly. Is it a wonder that when it was revealed they were faking it using wires they overthrew the royals almost immediately?

Yep. All dead.

@Macaroni C-Pony  
Nah, Scootaloo would be laughing her ass off. “Now you know how I felt my whole lifetime!”

So let’s discuss a possible take on the situation, of course from a non-canon/alternate-universe perspective. Let’s go back to season 8 for a second. Does anyone remember how Cozy Glow’s plan to eradicate all magic in Equestria came close to it’s realization?
 
Picture an alternate universe where the student six was unsuccessful in stopping her, their magical properties were stripped barren, and then Equestria came to submit under Cozy’s rule. Of course, she could dabble in the idea of immortality, but her lack of a horn would have made much of her future plans moot. Say she made a critical miscalculation, and her magic would also be taken from her. And of course, all magic in Equestria disappears with her unable to reclaim it. This means she effectively checked Equestria, but ended up checkmating herself also. No magic, no flight, no way to escape. She’s just simply imprisoned for the rest of her days, and that’s the end of her story.
 
I know it’s not relevant to the plot of the current canon, but it’s some good fanfic fuel.

I believe the result would be somewhere between a Wil E Coyote cartoon and Flugtag 88.

@Background Pony #55BA  
So, now literally everybody is Scootaloo?
 
 
Boy, looking down from heaven, she must be pissed

@Background Pony #55BA  
Ah, okay, that would explain a few screenshots I’ve seen with the wires and giant fans. I just thought I’d seen some screencaps of Zipp flying at one point, but she might have just had her wings spread and I’m misremembering.

@Background Pony #C6E4  
Spoiler  
|| According to a G5 child’s book, pegasi can’t fly. And royalty use wires to pretend flying. ||

What about the pegasus from Cloudsdale?

Have they said anything about the pegasi being unable to fly? If not, then they probably still can. Sadly the show’s writers long forgot that they tied magic to pegasi flight, earth ponies connection to the earth, and everypony’s cutie mark in the Season 4 finale. I don’t expect the G5 writers to suddenly remember that, but it would be nice.

Pegacide.

If it was sudden, they fell out of the sky and died. If it was gradual, they had to face the eventual destruction of their way of life and sole purpose for existing.

@Setsugekka  
You beat me to it lol. Darn it, Pipp!
 

@DerpyFast  
Falling with style

@Vortaxonus  
Even then, they could still glide.

this is assuming this is an immediate event rather then a gradual one.