Rainbow Dash is left like this. How does the series change?

[Gamer98 9]

Source: https://www.deviantart.com/ultrathehedgetoaster/art/Hand-Wash-Only-463205723

[Fluttershutter 2,554]

Well...her legs and neck collapsed but her wings look okay, so I guess it could be worse.

[tomatopotato 99]

7 hours ago, Fluttershutter said:

Well...her legs and neck collapsed but her wings look okay, so I guess it could be worse.

I beg to differ! RD is simply wearing soccer socks and she curled them down so they’re all wrinkly. And she’s trying to hide her face because she messed up Twilight’s mane again (season 1 episode 1 reference), which is why she stuck her head inside her neck. This is completely normal Rainbow Dash behavior.

[Night Sky 235]

I am certainly glad this didn't happen to Rainbow Dash, but certainly, there'd be consequences.

It would change more in the short run, largely depending on when this were to happen. In the earlier seasons, Twilight Sparkle might have had to sternly give a bunch of ponies a lesson about not being nasty to ponies who are disabled.

The Mayor might need to be reminded about accessibility and ableism. 

Behind closed doors, given her personality in the earlier seasons, RD would be difficult to be around. She'd probably be having a terrible time adjusting, She'd probably be lashing out and trying to do things she couldn't anymore and trying to blame others for it. 

The Rainbow Dash from Season 4 onwards has a bit more perspective about herself, so she'd probably be crushed, okay that was terrible, but also circumspect.

But in the long run, after the rest of the Mane 6 had snapped everypony who needed it back into line, nothing would change fundamentally. Equestria woukd still be Equestria, and Rainbow Dash would be a disabled pony living in it with her friends.

She'd probably have to give up the Element of Loyalty to another Pony, and that would be sad, but Twi and Princess Celestia could probably see to it.

[SkarletVoid 31]

Everytime she walks it makes an accordion noise now