I think it's offensive when it's said about speaking voices, but not offensive about singing voices. Black people often have the ability to be powerhouse vocalists, just look at Whitney Houston, Jennifer Hudson, Beyonce, Aretha Franklin, etc. They can belt. So I think that's what people mean when they say a singer "sounds black." I don't see how it's offensive if it's meant as a compliment. It's not like "ew, you sounded so black." It's "oh my god, you have such an incredible voice that I thought you were black!" It's pretty much admitting that black people are superior singers.
I thought Anastasia was black the first time I heard 'I'm Outta Love' on the radio as a kid.
I don't think it's offensive... It's more of a compliment since "black" voices sound incredibly good. Idk I think it's just how you say it but I think of it as a compliment.
But that's just my opinion
