Ok, here is what I gather from the trailer, and what I think it means:
Basically, the movie takes place in a time when LOTHT did happen. The young kid (with the

shirt) either watched the show when he was young and bought a shirt, or his father/cousin exc. remembers the temple and gave him his t-shirt. Either way, the young kid has some prior recollection of the show, because he remembers the Shrine of the Silver Monkey and Olmec.
There are a lot of other things one can gather from the trailer, but one thing I believe is that the movie could be a promo for a game show that would follow.
One thing I talked about a few months ago is that the reason LOTHT wouldn't work now is because the show (which is geared for kids) would get 85% of viewers from people above 18 years old. Now, with the movie, young kids would be excited to watch the show, and people that remember the original would be just as hyped.
I wouldn't be surprised if you see a "Do you want to
be on the Show?" promos during the commercial breaks of the movie.
Anyway, this is pure speculation, but I think it's an opportunity Nick wouldn't pass up.