The two theories that make the most sense to me right now are:
1. He ended up walking somewhere and running into trouble beyond the current search grids. He could be laying in the elements and simply not where someone would be looking for him... Or...
2. He was picked up by someone(s) unknown, under the pretense of helping him get back to the hotel, and taken somewhere and dumped. Again outside the search area...
I know they have info from Google timeline as far as where he walked that night but it's also been said that may not have been entirely accurate and/or that the phone stopped tracking him well before his final location. The wife said his phone had a low charge too. I don't know about the android phone he had but on my iPhone; if it goes into energy saver mode then certain background events, like sending location data, may cease. There was recently the suggestion that Tyler had actually made it up by "Hampton by Hilton" instead and that puts him in a spot for something foul to more easily have happened to him, imo.
If someone robbed him outright or if it was a hit and run, they would have just left him there. People don't tend to take bodies and hide them in random occurrences like that.
So it makes the most sense to me that he willingly got into a car or left the area in some other fashion. It's always possible he's still near Easton. There are cases where people have been found mere feet away from prior search areas BUT with the amount of time that has passed, this seems less and less likely.