Uhhh, a great artist is born here!!! Good choice not to tell us more, I think anyone would instantly steal it and sell your genius plot for ten million dollars.
Seriously, your plot idea reminds me of JP: Redemption and is kinda cliché (a badass version of Tim, lol.). The scenario would feel like the second or the third movie with all the decayed buildings, and we saw ENOUGH of that! Any true JP-Fan would want to visit and experience the first movie, and thats the only way to get drama and story in it, a man alone on an island wouldnt be cinematic enough, there wouldnt be enough other characters for a RPG. Oh, and Jurassic Park: Dark sounds like a gothic version of JP with vampire dinosaurs
Also, why does everybody think openworld and RPG is the ultimate game design, same thing in Bttf. It suits for some scenarios, but not for all and definetly neither for Jurassic Park nor for Bttf. Yeah it would be cool to explore the park as a visitor, but that would be an own project or maybe a side feature, but it wouldnt be a good game! Why? Because JP needs characters, certain and well designed situations with scripts, and thats something openworld games cannot do, the player would have too much control and the possibility to not experience a situation like the designer intended it, like a T-Rex outbreak or something. Also the island does not offer so many interesting locations to justify an openworld-RPG, telltale should concentrate on the important locations from the movie.
My only request on Telltale is to pay attention to all the details, use enough technology to get appropriate graphics, do the FIRST movie and create situations that are playable (some sort of third person stealth and survival elements) but yet reminding of the famous scenes from the movie like the raptor hunt in the kitchen ot the T-Rex outbreak etc...
And PLEASE use the original soundtrack, I dont know if there are license issues but I want the original tracks from the first film