These are the scenarios I see involving the LE and family silence, post warrant to search facebook/whisper...
1. They found real evidence that she planned to run away and make it look like a disappearance, and perhaps plans to dump her luggage too. This took it off LE's top priority list and maybe family doesn't want to put too much out there for fear she could be stigmatized later (like job searches/future)? I would think they would still put out some message like "Katelin, we love you regardless of anything that has happened and just want to confirm your safety. Please give us a call so that we know that you are okay." That would at least "solve the case" and it could just be an internal issue.
2. LE found something suspicious on her facebook, such as a planned meet up or just contact with a known criminal and fear she has been or will be harmed and do not want to release any info until they locate her.
3. LE does not think she made it to the mall (I won't go into who/what/where as no one has been named a POI or suspect) and is collecting and testing evidence, waiting for a slip up, trying to disprove stories and alibis, checking any/all footage they can find, etc.
4. They are at a complete loss and/or are letting this slip through the cracks for whatever reason(s).
Scenarios I would doubt based on the very limited info the public has been give:
1. Suicide or known mental health issues or physical health issues. I think they would put out a message that she could be a danger to others or herself, as they usually do on those types of things, or that she is in need of medication, etc.
2. Random abduction. Of course there are Jesse Matthews type evil people out there, but this was daylight in a very specific time frame from last seen (if all given accounts are accurate), and she was not known to be under the influence or in distress. Unless she took a random cab ride from a driver with bad intentions (such as JM). But I think in broad daylight at the mall, and the fact that she wasn't lost and had a plan supposedly to get to the airport without a cab, makes this less likely. (again this relies on all of the accounts given being accurate, but if they weren't true, then that would honestly make it even less likely it was a stranger abduction...)
3. Casual change of life. I can't see someone just casually wanting to change it up or needing to clear their head, and going to the lengths of dumping their luggage and wallet and not contacting a fiancee or family for a full month including Christmas. I think if she ran away from her life, something big had to be going on. Lots of debt? Abuse or threats by someone? A crime? Something life altering and seemingly inescapable without changing "identities" completely. Also, someone would have to be harboring her and I can't see too many genuinely nice, law abiding people harboring someone for a month when LE and family are looking for them, if she just needed a bit of space. Anyone harboring someone from that many people would have to be involved in criminal activity themselves or understand that she had a big reason why she needed to hide. JMO though.
