No The Departed plot was a direct remake of a Hong Kong film called "Internal Affairs". There is/was some talk that particularly Nicholson tried to base his character on Whitey, but it was a completely different story.
And FWIW at the time that movie was made (06) Bulger was missing and presumed dead, he since was captured in 2011 which is what kind of completes the story & makes it very film worthy. Ironically for myself, I have to admit I was somewhat disappointed at the time of The Departed because having read Black Mass and heard of the alleged 'partially based on Whitey Bulger' background, I thought the Departed story was TOO UNLIKE Whitey's story. Again, that wasn't the films flaw as it was simply a retelling of another fictional story.
I can claim some consistency in asserting that when Whitey is missing or dead the story is worth telling in its whole. But it better be damn careful about glorifying this guy. This isn't a fictional godfather where you can analyze the killing of your naïve brother or betraying brother-in-law. Whitey killed 2 young girlfriends, an innocent guy who happened to give the wrong guy a ride home and numerous others ONLY to protect himself from getting caught. That he did this while manipulating a stupid FBI agent (or agents) and convincing an entire Boston neighborhood that he was their protector not corruptor is very interesting, but its nothing to be celebrated.
If the film used or consulted with the two Globe writers that authored Black Mass it has a chance of being true to the despicable reign of terror that Whitey perpetrated. But looking at the credits (two relatively inexperienced movie screenwriters adapting the book), Director Barry Levinson drops out and all the pretty Hollywood people in the movie (Depp, Sienna Miller, Cumberbatch, Dakota Johnson) I don't have high hopes for this being a true-to-life retelling of the scumbaggery. Just read a review of the script that was very unfavorable (story told through the eyes of Connelly, the now in jail dumba$$ FBI agent that thought he was using Bulger as an informant while in reality Bulger was playing him, Connelly = Joel Edgerton). The problem with this is Connelly was either a complete boob or a selfish, money grubbing sociopath - probably a little of both but more of the former. Sorry to be Debbie Downer, but this might bomb.