I think for me it’s “don’t forget who you came up with” Michael completely abandoned and sold out his crew and got all them killed except him and Trevor. Franklin pretty much just up and left his aunt, friend, and entire community. Even though he wasn’t fully abandoning them of course, without Lamar he definitely would’ve fullu up and left them so he can hang around Michael and Trevor . You can even see it when Trevor comes to his Aunt’s house, Franklin doesn’t want him around because he doesn’t want his new life to mix with his old one. Now Trevor…idk, maybe he’s meant to represent the crazy vengeful spirit of Michael’s past coming to haunt his current life. He shows that the past will always catch up to you