At the end of Loki's second episode, we met Sylvie just as she was launching an attack on the Sacred Timeline. Using the TVA's pruning devices to cause chaos (in an effort to give her enough time to find and kill the Time-Keepers), her mission might have been a success had the God of Mischief not intervened and taken them both to Lamentis-1.
Unfortunately, we never got to witness the fallout from Sylvie's actions, which was a surprise when many fans wondered if it might be the start of something much bigger. The TVA ultimately managed to clean this mess up off-screen, of course, and Loki director Kate Herron has now elaborated on why that was.
"I don't know if we ever saw them clean it up. I think it was always something that happened off-screen," the filmmaker explained. "You saw her do her rampage kind of through the TVA, and we're with Loki's POV, right? And then they end up on Lamentis. So it's kind of like, the TVA have been doing that while they've been on Lamentis."
Herron acknowledged that there's potentially "something more to be explored" with what happened, but as we know, she won't be responsible for telling that story after confirming plans to move on from Loki.
She did, however, reveal that we nearly saw more of Sylvie's attack on the TVA. "What we used to have actually was, so in Elissa [Karasik's] script, basically, it carried on. She went into the TVA, and there was...We called it 'The Rampage.' And originally, I think in the script, that was massive. It was like her going through the TVA and taking everyone out."
Ultimately, that attack on the Sacred Timeline served a purpose, even if the ramifications weren't acknowledged in a direct way. Seeing as this first season wrapped up with the recreation of the Multiverse, seeing anything similar before then would have arguably lessened the impact of "For All Time. Always."