Yeah you are not wrong. It is set in the Forgotten Realms, like many other games before. Still Neverwinter Nights and Icewind Dale did make some nods here and there to the other games set in the series, but they played in different times and/or regions, hence the different name according to their setting.
It is also safe to assume that many players of BG1 and 2 have never played or read anything else in this setting, I sure never did. It was just an RPG to me at that time so that is all that I know of the setting and the lore. Therefore I associate the city of Baldur's Gate and the name directly with the story that unfolded in these games, this includes locations, characters, items etc.. So now we have a game that is distinctly and deliberately called Baldur's Gate 3. So I am expecting not a game that shares the same setting like Neverwinter Nights, or the gameplay like Icewind Dale, or the spiritual successor like PoE, but a real successor to the games. Now I do not need a continuation of the story, as the arc seemed finished, but a game that is clearly defined by the events of the story and the BG1+2 game itself. At this moment in time there is nothing really. It is just a Forgotten Realms RPG.
I am assuming there will be more things that are added, I just do not think it is enough to put a town (Baldur's Gate) in and a character (Minsc), to justify the Baldur's Gate 3 name.
It's entirely possible that we get a lot. It's also entirely possible that we don't get much at all. Given that the story arc for 1 and 2 has been neatly wrapped up, we could spend this entire game in the Shadowfell, and keep getting askance references, and I'd be fine with the name. All of the Dragon Age games have been centered around different parts of Thedas, with a different protagonist, and yet, they are all Dragon Age games. This may seem like an apples/oranges comparison, I thought so myself as I was typing it, but the parallel is that we are running in a game, in a realm that has a history that predates anything we've actually played in it, the same for Thedas, and we're plopped in at a, and I'm going to say random here for lack of a better term, random point in the timeline.
For Thedas we started in the 5th blight, but the game has a history that stretches out well before that, and here, we started with the Bhaalspawn saga, and moved forward in time. The only issue I have with the position of "some people may not have played anything but BG and BG 2" is that that doesn't nullify everything else that has happened in the FR in the interim. We may well end up with players that have never played either one of them. Canon novels, games and table top modules have happened between then and where we are now in the timeline. There's also the "more things will be added", and I'd like to add "where does the rest of the game take place?" to the mix. Along with that, who, as NPCs, play a prominent role in the rest of the story beyond what we're playing with here? The "where" may not even be as important as the "who". Again with my parallel to the Dragon Age series, where there is a common thread throughout that ties them all together, aside from just the setting. Where we're at right now doesn't actually lend itself to giving too much of that away, and it's a safe bet that that's why we are where we are.
So before I start thinking "this isn't a BG game", I'm going to play the rest of the game first. The bard in me says I don't want to judge the game based on what amounts to a really long teaser trailer. The part of me that sat in the theater and literally cried when Peter Jackson revealed Rivendell for the first time in Fellowship believes that there is plenty of time to tie this game to it's name. It also secretly hopes that I don't have to eat these words later, because that's not outside the world of possibility. However, given how much of the game we don't have, and have no real clues about, I'm willing to sit back and say "let's see where it goes before we throw it under the bus".
