Wheee! Devils Advocate Time!
Of course something else would work. You guys have enjoyed linear Cpunk experiences for years. Blade Runner - same ending every time, still fun to watch. How many times you read Neuromancer or Hardwired? Watched the Matrix?
So I think we could have a great, an amazing non open world Cyberpunk 2020 game. Absolutely. As for true to the source...CP2020 is based on teh above stories and they are not open world. True to your source is setting, gear, etc. Not gameplay style.
And even open world has flaws. Flavour loss, less resources for intimate settings wherever you look, can't devote a campaign to -just- playing a Netrunner, with all your resources focussed on that.
Open world without Co-op would be less than Open world with Co-op, for example.
So open world is far from a guarantee of quality and lack of it hardly decides the authenticity of the game experience.