When Steph Curry was a rookie
1) It was Corey Maggette's last year as a Warrior. He remains the crown jewel of pure chuckers. Even Kobe Bryant would blush around a shotjacker like Maggette.
2) Monta Ellis was already on the squad. Another gunner who never met a shot he didn't like
3) Don Nelson HATED rookie players
4) There was a really long era of the Warriors just sucking hard in the draft and in general. Some truly ugly years.
This is an example that a teams circumstances can make rookie player evaluations complicated. A player on a bad team in the East on a roster full of injuries around him is a different story than a player on a solid team in the West with depth.
Things you can initially determine
A) Can the player operate at NBA game speed
B) Will the players fundamentals erode, or not, given either playing at NBA game speed or attempting to do so
C) Can the player, at minimum, defend his "own weight" i.e. can he play without being a defensive liability on the floor.
Early burn is a hard gauge because part of the game is Move/Counter Move. You have a certain arsenal of moves and tendencies. The league gets a "book" on your skill set and adjusts. You must counter adjust to their adjustments. It's like game, a chess match, within the larger game itself. Given time, the players who can keep counter adjusting are going to show bigger leaps in development.
Joe Dumars is the gold standard. He's more known for being a mediocre GM. But in his prime, he was maybe the most underrated "complete" shooting guard in his era. You were not going to pin down what he was going to do. He'd adjust both long term, across a season, but also within a game itself.
It's only been a handful of games.
Much of the "hype" is really brands and networks trying to get a return on their investment. Every year, a new crop of rookies come in, and if you don't generate buzz early, you fall by the wayside in terms of marketing appeal. Tristan Thompson is an energy guy who has decided this year to stop caring. But his Q Rating has skyrocketed. Why? He's banging a Kardashian. "Hype" is not always relative to your actual status as an NBA player who can help a team win.
Trying to annoint guys stars or not now, is just a byproduct of buying into the sports media hype machine. It's not what someone really thinks, it's what they think they think, but it's just a regurgitated tagline shoved into their head by Nike's marketing department. Rookie lists work the same. Look at the agents of said players and who is sponsoring them, and the narrative is much clearer. There's a guy like Ari Gold telling fans who is awesome or not, most of them just believe what they are told.