In the room with the ARK prototype you'll find Catherine's to-do list and the following message, both indicating that she already loaded all the scans onto the ARK but also that some people did not get scanned.
Quote:"I have decided to finalize the ARK with the scans we have. I'm sorry for all of you who wanted to go but didn't get a chance to scan yourself before the project was put on hold. It's been two months since I've added a scan and I don't see how I'll ever be able to win back the support you all showed when we started the project. I'm sorry. I never meant for anyone to take their lives, it was never my intention to fool anyone. I just wanted to save something."
I think I saw a note somewhere telling people at Omicron to go get scanned, so maybe they didn't make it on board? I can't confirm that one though.
Brandon obviously got on the ARK, I'm more interested in knowing if there will be two scans of Catherine on there.