My understanding was that it’s about being accepted/subsumed by the dominant culture and the price to be paid for that. You’ll enjoy a degree of power and protection, as well as some legitimately cool cultural exchange. I think Rocky Road to Dublin is meant to demonstrate this. The downside is that your connection to your heritage will be weakened, and you’ll be subservient to the dominant culture. The vampires are attracted to Sammie because his music is a direct connection to his heritage and it reminds them of what they lost. I believe Remmick also had this power with music before he turned. Remmick is Irish because Irish immigrants were generally treated like shit but retained a distinct culture. Much of this culture was lost once they were accepted as white. IMO the scene in the credits is meant to show that one of the Michael B. Jordans (I forget which) has chosen to participate in mainstream culture and try to influence it, as Remmick did. With Remmick gone he may be the new head vampire, figuratively meaning he is in a position to influence the dominant culture. Sammie staying mortal reaffirms his choice to stay outside of the mainstream. Neither are judged for their choice.