About Discord, I think he was fine because the mane 6, as well as the entire Ponyville, were questioning him and being suspicious because of his previous actions. That made sense. They did the exact same thing with Sunset Shimmer in Rainbow Rocks, Babs Seed in One bad apple, princess Luna in Luna Eclipsed and Diamond Tiara in Crusaders of the lost mark. If the MLP team made a sequel to the 2017 MLP film, they would do the same thing to Tempest Shadow, which would make sense for her character.
My problem is that they didn’t do the same thing with Starlight, even though she ended up doing worse things from season 6 to 9. Nobody in the mane 6, not even Spike, not even Ponyville, had questioned her. Everyone is absolutely supersticious about her. Why is ok to question Discord but not Starlight? Why is ok to be suspicious about him but not Starlight? It doesn’t make sense.