There is no hip hop costume seems like what you are actually talking about is African American/Black stereotypes?

Hip hop is a genre and hip hop artists can come in many forms.

• Frank Ocean/ Vince staple - deep, intelligent. experimental - alt
• Tyga, Megan Thee Stallion - 'swaggy', boastful.
• Lil Nas X - poppy, mainstream radio friendly.
• Kendrick Lamar/Vince Staples - hard hitting lyrically
• G Funk - old school Warren G etc.
• Jazz rap - Guru Gang Starr, Nas, Tribe called quest

How can they all be lumped in together as a 'costume' when the only similarity is that they're black. You wouldn't do that with white artists.

Then there's white hip/hop

• Beastie Boys - don't know what to call their style but they are rappers.
• Mac miller
• Eminem.

Anyway, rapping in tracks doesn't mean that BP are appropriating black culture, it's a vocal delivery style and they are using it in pop songs.

PS. I do acknowledge the mistake that was Lisa's KTL braids but at the same time - I don't expect all countries in the world to be up to date with the latest discussions on appropriation that are being had in the west. Afterall, they are culturally different and don't have the same history so have to learn what it is not acceptable for a western audience.