It'll rate highly. Then there'll be a backlash like there was for Fallout 3 and Skyrim.
It's really hard to judge a game like Fallout 4 in a short amount of time. Just give it a 10 and avoid anyone complaining or sending you death threats.
The Witcher 3 is a buggy mess even after more than 10 updates and that didn't prevent it from getting high scores and a lot of 10s. If Fallout 4 is a good game, it will get high scores regardless of technical issues. This is the world we live in unless double standard.