That has neither been confirmed nor denied? It's been in development since 2012 afaik. So either extreme quality/depth, or lots of extra content in the form of quests or a balance of both, but that's all speculation, nothing concrete from what I know. What I can put faith in, is quality.
As to why Preorder THIS specific game that I agree with based on their reputation, from CDPR themselves -> "Also, since pre-orders are live, you might be wondering if there’s any point in placing an order now. Yes, if you want to give us some extra support. Pre-orders help us build anticipation — the more copies you pre-order, the more likely it is for us to get retail (both digital and physical) behind the game. Therefore, if you like what you see, we will appreciate you "voting yes" for CP2077 with a pre-order. If you are still hesitating though, we would rather you wait for more materials or reviews. Our goal is for you to truly enjoy CP2077 and not regret a pre-order.
Take care and looking forward to seeing you in Night City! CD PROJEKT RED team"