Huh, that is some weird game behavior. As I said, year old saves experiencing issues is common and, dare I say, "normal". Especially if those saves went through multiple versions prior to your year long hiatus.
But... this, this is not something I have ever seen anyone report. When you press new game, it just hangs there? Doesn't ask you if you want to do a regular game or skip to Phantom Liberty? And the game is still responsive afterwards? As in you can then press load game and it'll react?
If the answer to all of this is yes, that's a new one. When you say you already did all this basic stuff
@LeKill3rFou pointed to, you mean you did the full clean install, right? Including removing any residual files in your install path as well as everything CP2077 related located in userdata. I'm only asking because I've seen too many people say they did a clean install of the game but all they meant was uninstalling and reinstalling the game. Cleaning up the residual files is extremely important.
If you did, frankly, a clean install should have fixed this right up. This is a very unusual bug. Definitely worth reporting to CDPR:
Welcome to CD PROJEKT RED Technical Support! Here you will find help regarding our games and services, as well as answers to frequently asked questions.
support.cdprojektred.com
If you already did the clean install, what else have you tried? Just so we don't end up enumerating a bunch of things you already tried.