Ghosts and Base Game

[Ndainye]

I'm working with a group that's putting together a base game hood. Trying to keep everything as clean as possible, but have heard conflicting reports regarding packaging ghosts on lots in base game.  I've read that any ghosts in packaged neighborhoods prior to UNI will have a likely hood of glitching and I've also read that as long as the ghosts don't know anyone other than those on their lots that there's no problem.  Anyone have experience with this?