I heard some people mention AU ideas where other ponies (friends, family, acquaintances, etc.) learn about the Mane 6's treatment of the CMC during the Gabby Gums fiasco, and those ideas got me thinking. What if those ponies finding out about this have drastic repercussions on future events in the series?

Ex: Shining Armor finds out about Gabby Gums and the way his sister and her friends treated the CMC. Furious over this, he decides not to invite Twilight or her friends to his wedding. As a result, nopony finds out about the fake Cadence until it's too late, and the changeling invasion of Canterlot goes off without a hitch.

What do you guys think?

That sounds like an interesting idea. Not only Shining Armor would get angry, but others as well. Another example could be Rarity’s parents and they could disown Rarity and take Sweetie Belle as she and the parents might move out of Ponyville.

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Or maybe her contacts in the fashion industry find out and cut ties with her, ending her prospects of being a big time fashionista, and leading to other consequences as a result of her absence.

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Not only that, the Wonderbolts could catch wind of what happened, especially the rain cloud part, and cut ties with Rainbow. Making her lose any chance of becoming a Wonderbolt.

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I think it's best to say that it's a good idea. No doubt the wonderbolts cut ties with Rainbow Dash. And I wonder what will become of Spike?