In The 4400 people are abducted and sent to the future. In The Crossing people randomly appear from the future. The 4400 was on the SyFy channel and lasted for 3-4 seasons. The Crossing premiered last year and was cancelled after only one season.
The basic premise is this: a group of people on a plane take off and after flying through a storm land at their destination 3 hours later. However, in those three hours 5 years has passed. So obviously the government is suspicious and families are happily surprised (albeit also potentially conflicted as they have moved on with their lives). At the surface seems kind of intriguing. Then you have a couple characters starting to hear their own voice in their mind and realize that when they do what the voice tells them people are saved. The pilot episode ends with the entire group that was on the flight arriving where their plane is parked because they all felt they needed to and we are told in a voice over that this is "just the beginning".
TV Shows like this can do well and can be enjoyable, albeit sometimes just from a cult following. Unfortunately in this first episode none of the main characters connected with me, which I believe is an essential piece to a tv show being successful and enjoyable.
I'll probably watch episodes here and there or awhile to see if it connects with me but although the previews made me really excited for Manifest, the reality is a pretty disconnected show with weird things happening to it's characters. There's a little mystery about why they disappeared but oddly enough that's the least intriguing part of the show right now. The show seems to be setting up the premise that it has something to do with God or a higher power. However, it could also end up following The 4400 or The Crossing and involve time travel or another solid fallback is alternate realities. But one of the things that makes the "what did this?" angle less intriguing is that they haven't given us any reason to believe it's anything other than a higher power, time travel or alternate realities which feels very stock. I guess we'll see how it goes and if they can start to turn things around in a meaningful way over the next few episodes.