So other than being a real time with pause tactical party based RPG, and being set in the city of Baldur's Gate with D&D rules, what's the connection to Charname and his ascent (or non ascent) to godhood?
Thing is, Dragon Age: Origins and Pillars of Eternity 1 & 2 are both effectively BG3. Especially DAO, which had characters which were expies of the companions from the first two games (Alastair = Ajantis, Morrigan = Viconia, Leliana = Safana, Sten = Valygar, Oghren = Korgan, Zevran = Haer'Dalis), spells which were direct cognates of their BG equivalents, and locations that corresponded exactly to places in BG1 and 2 (i.e. one large major city, one smaller town, and various adventure places spotted round the map.) In fact, DAO was effectively BG3 with sufficient alterations made to avoid the wrath of WOTC's lawyers.
(It was also the second to last genuinely good game that Bioware made, but that's by the by.)
But... yeah, is this going to be actually a worthwhile successor or just a sequel in name only. And since it's forcibly set in 5E, this means it's set at least 100 years later than the first two. Which means of the characters that could have appeared in BG1 or 2, only the elven or (at a stretch) dwarven ones may find themselves appearing. Now if that means we get Kivan or Xan (WE'RE ALL DOOMED!) or Vico floating around, that's one thing.
That being said, given that it goes into detail re. illithids, what's the betting the big bad will be the Alhoon from one of the side quests in BG2. (An Alhoon is basically an illithid lich, if you don't know). Basically, in BG2 there was a number of side quests in Athkatla which touched on people controlled by, or directly meat-puppeted by, agents of "the Hidden," and it was gradually revealed that "the Hidden" was a group of illithids who hung out under the city, and you could follow clues to find their lair in the Temple District sewers which contained an Alhoon as a bonus boss. You had to beat him, actually, to get hold of one of the parts for Crom Faeyr the legendary hammer. However, since an Alhoon is an illithid lich, and given that you never actually find his phylactery, what's the betting that after a hundred years he's come back and is trying it again in the city of Baldur's Gate? There is mention that he was playing a very long game and you may actually have stomped an evil overlord in the making without realising it.