I just checked when (flawless timeline) Twilight lists all her adventures
she says "saved the world" a few times, but nothing that sounds like a specific Arinos timeline event

>>42392887
We could have more major contradictions, like simultaneous Rarity x Twilight and Twilight x Trixie, that would be more evidence for 2 timelines
If flawless and arinos show up in the same episode, the theory is confirmed false