I would disagree. It is still open world. I can drive around in a vast area without any problems, go to different cities, discover lonely places and check out nearly everything I want. I can solve problems in different ways. Except for some high level areas where I first have to do some very basic/trivial things first.
Other open world games have areas you can't really visit in the first days as well and they are still called open world games.
Here are some quotes from the wikipedia definition of open world games that indicate that "open world" is neither a clear cut definition nor an absolute decree that you must be able to go absolutely anywhere on day one.
"Open-world games still enforce many restrictions in the game environment, either because of absolute technical limitations or in-game limitations imposed by a game's linearity".
"While the openness of the game world is an important facet to games featuring open worlds, the main draw of open-world games is about providing the player with
autonomy—not so much the freedom to do anything they want in the game (which is nearly impossible with current computing technology), but the ability to choose how to approach the game and its challenges in the order and manner as the player desires while still constrained by gameplay rules"
"Some open-world games, to guide the player towards major story events, do not provide the world's entire map at the start of the game, but require the player to complete a task to obtain part of that map, often identifying missions and points of interest when they view the map. This has been derogatorily referred to as "
Ubisoft towers", as this mechanic was promoted in Ubisoft's
Assassin's Creed series"