So I played a couple hours tonight. I logged in close to a companion quest, because I got a distress beacon as soon as I logged in. Was some astronaut that was part of some deep sleep project that had no idea about the war. I unlocked the part where I build their thing as my camp so they spawn there and give quests/etc. After that I did a few more interaction/quest starts (Vault, the bar nearby, actually talking to the overseer). I have no clue if it all unfolds differently for a new character vs. an established one, although the Overseer did ask me if I had done a few key quests earlier (the vaccine quest being the big one), so I suspect a new player is directed to those quests.
The NPC interaction is a little laggy in terms of the dialogue options showing up, but functional. The companion quest had a bonus to avoid fighting an assaultron if you had 8+ int, although earlier part of the quest spawned a fuckton of super mutant suiciders on me lol. The lower level quests seem to have less stat requirements...like one at the start only required 2 or more perception to get a guy give up a robbery. The game also has some low stat options...the bar at the start had a 1 charisma or less one, for instance. They also have a few instanced areas, presumably because choices later on will impact those areas and it would be hard to have that uninstanced in a multiplayer environment. There also seems to be different response choices given that let you be an asshole, a nice guy, or a vault tec loyalist in some cases. Raiders are KOS, but if you did another quest in the game, a raider Mr. Handy you made "friends" with will get you an introduction with its aligned raider faction so you can start interacting with that raider faction (there are other raiders not aligned, plus mothman cultists, which are KOS always. Although there is a legacy quest to summon mothman and get the blessing of mothman, so I might need to do that quest and see if the cultists will accept you at that point).
I think if you havent played the game at all, you'll probably be pleasantly surprised and it will probably scratch that fallout itch. I've played the game since beta (although mostly nuclear winter vs. the PVE stuff for the past 8+ months or so), so I've already seen most of the original content. The NPCs will probably give a lot more impact to many of the areas, though.