So there's been some updates to the Archive request board, but if your characters weren't killed and you have a solid reason for bringing them back then it might be possible. I'll be honest, I'm not 100% sure when this went into effect and if it will effect anyone that's returning to gear up for the timeline skip. Hope that helps, good luck!
Edit: On the real, I'd reach out to a MOD or ADMIN for clarification on the subject.