Let me Answer some of your Questions for you! This will be based on what's known so far. (Spoilers, Of course)
JP Jeep # 29 Will make An Appearance, For anyone who doesn't know, It's the Jeep Hammond And Genarro Show up in. Cannon states that is was Returned to the Garage and has been sitting there for the past Twenty years or so. Some believe it may be Re-Done up to Match Nedrys jeep, Which was Destroyed after Filming.
Colins a Dedicated fan, He will most likely Build upon the Raptor Claw more; It was Intended to be Ended with Eric Kirby showing Dr.Grant his "New" Raptor claw on Site B.
The Canister was Covered in mud, As Stated Prior, Colin is a dedicated fan, Thus he'd want to fit in with the rest of the wide universe of JP. Which means the Canister was Destroyed by the Rex in JPTG. Colin may Dissmiss JPTG As It's own JP Universe However, Due to there being a Book version of Site B Map on the wall in one of the shots.
We may see Nedrys Body, I'd imagine Patel Corp. Most likely removed it during Construction. (Feel sorry for the suckers stuck with Disposing it, Twenty years of Decompisitons, Yeeuck, Although it's most likely just bones by now.)
The T-rex, As well as all the Other animals on Ingens Site A, Would've had to been Put Down. If they hadn't died out from lack of Food Source Already. Patel would wish to rid most everything that Resembled the Old park.
The Only character from the First film called back Was Dr.Wu. So, Including characters stranded from the Old park makes little to no sense, As they probably would've died by then.
Hope this answered some of your Questions!
Cheers!
-Paden
Life cannot be contained, it breaks walls, crashes through barriers sometimes painfully, but uh... Life uh, finds a way
