D&D books generally found in the Dungeon Masters Guild website are not canon. The reason why is because the information about Minsc and Boo contradicts what the comic book series set prior to Baldur's Gate 3 have about him. And then there is Xzar, who in the Heroes of Baldur's Gate tabletop adventure (which can also be found in the Dungeon Masters Guild website) is revealed to be a Bhaalspawn, but Minsc and Boo's Journal of Villainy makes no mention of Xzar being a Bhaalspawn, meaning it is not canon.
Yup, it also says imeon is still alive, which contradicts stuff from Murder in Baldur's Gate, a pretty major plot point (conditions for bhaal's return).
Keep in mind the Heroes of Baldur's Gate adventure is by the same author and not published by wotc either, and def not canon.