Yes I'm going by the books and the books are a somewhat different from the games, but the only thing to note from the books is the few key scenes from the final end when Bhaal got resurrected, nothing else matters from the books (so basically tying the Player's versions of the events with the final end from the books). Would be a nice touch to show that the players of Baldur's Gate to find their previous character laid buried and honored as a hero if he didn't choose to become a god and you can find the Sword of Chaos inside his tomb.
OR alternatively if such a idea is not well recieved in this forum, maybe the Duke's Daughter from BG1 and Siege of Dragonspear? If you all played the game then you all know what happened. Reason I suggest this is because we believe BeamDog will not have this plot point resolved, and it would be a good chance for Larian Studios to tie up a very loose end from Siege of Dragonspear.
EDIT:
I forgot one thing, but if you all do end up doing it then it would be cool to hear "The Stage is Set" when you find the tomb from the BG1 OST.
For the record, the novelizations are abominations, trust me, I've read them, and they don't necessarily need to be considered canon over the games. Not just because they don't do the games justice, but they also seriously flub up the lore of D&D while trying to be considered canon. For example, Angelo, the corrupt Flaming Fist officer, is a Grand Duke in the novels. It is wrong on so many levels to give a D&D character that only appears in a D&D game a high position of power, because Volo's Guide to the Sword Coast never said that there was a member of the Council of Four by the name of Angelo, only Belt, Liia, Entar and Eltan are the Grand Dukes of Baldur's Gate, and no, you can't shoehorn in a 5th member. Also, Bhaal got resurrected in the Murder in Baldur's Gate tabletop adventure game, which takes place 123 years after the Baldur's Gate games and novels.
I've played Siege of Dragonspear, and I know what you are getting at. But try to look at this from a brand new perspective. In the intro of Shadows of Amn, the narrator makes it clear that the people of Baldur's Gate figured out that the game protagonist is a Bhaalspawn, and also because of "dark circumstances" (which involves Skie Silvershield), the game protagonist is forced to leave Baldur's Gate. But in the novelization, Abdel Adrian got away clean. The book doesn't fill in the gaps between the first Baldur's Gate novel and the Shadows of Amn novel, it doesn't reveal how Abdel was captured, and as far as the people of Baldur's Gate in the novel know, they don't know that Abdel is a Bhaalspawn.
My point is, the game protagonist seems destined to be viewed as a monster regardless of his/her deeds, while Abdel goes on to be seen as a hero, even though he might not deserve to be called one. The reason why I don't consider the game protagonist and Abdel to be the same character is because of how different their backstories are.
Abdel: Abdel was born in 1343 DR, and Gorion did not was not the one who rescued him. Abdel was rescued by a paladin who was a friend of Gorion's named Sir Daesric the Pious. The paladin saved young Abdel from a group of deathstalkers. Though Daesric knew Abdel is a Bhaalspawn, he could not bring himself to kill young Abdel. So he called upon his friend Gorion to raise the child as a monk of Torm and though reluctant, Gorion agreed. Abdel was taken to Gorion's home in the library fortress of Candlekeep, where he was raised as Gorion's own son, and Gorion was
unaware of his heritage and nature as a mortal child of Bhaal (EVEN THOUGH HE LEFT A NOTE LIKE IN THE GAME REVEALING TO THE HERO WHAT THEY ARE). The Hands kept watch over Abdel to make sure he showed no signs of evil but when Bhaal was killed, they gave up the effort, and Abdel departed Candlekeep in 1360, 8 years before the Baldur's Gate story to start his life as a "sellsword" or mercenary for hire.
"Gorion's Ward", the game protagonist: According to the first game's beginning cutscene, "Gorion's Ward" has lived in Candlekeep for nearly 20 years of his/her life, which means Gorion's Ward was born in the year 1347 or 1348 alongside Imoen, who was also 20 years old in 1368. Unlike with Abdel, Gorion knew that the game protagonist is a Bhaalspawn, because he personally rescued him/her from a group of cultists who worshiped Bhaal, trying to sacrifice the young Bhaalspawn they had collected, including baby Imoen and young Sarevok. The game protagonist's mother was tasked to sacrifice the children, but before she could sacrifice the infant game protagonist, Gorion slew her and took in the game protagonist and Imoen as his children, leaving young Sarevok behind.
I bet you are wondering where am I getting at? I'm saying that it is possible to see the Baldur's Gate protagonist and Abdel Adrian as two separate characters. Gorion was given Abdel years before the game protagonist and Imoen were born, and then sometime in the late 1340's he personally rescued them, and he raised all three of them up until 1360, the year Abdel got old enough to leave Candlekeep, then in the following years up to 1368, the events of the Baldur's Gate game plays out up to Siege of Dragonspear, the game protagonist becomes a disgraced hero because of Jon Irenicus framing him, then the events of Shadows of Amn play out and then Throne of Bhaal, then sometime later Abdel shows up to Baldur's Gate, and through certain circumstances (possibly being hired for a job that would help him be viewed as a hero), Abdel is written into Baldur's Gate history as the hero of Baldur's Gate who killed Sarevok even though he wasn't involved. History will remember him as a hero whether it is true or not, while the game protagonist lives his/her life alone or with a romance interest without any part of Faerun knowing he/she was an adventurer who deserved to be hailed as a hero.
In other words, there is a way to include Abdel as the "canon" hero of Baldur's Gate without accepting the novels he is in as the canon Baldur's Gate story and accepting the games instead (as long as your version of Gorion's Ward chooses not to ascend to godhood).