Old discrimination, future shame?

Sometimes, while reading old books, you can find awkward sentences like this one:

There they lit the fire and Nab and Pencroff, obviously on cooking duties (one being a Nigro the other being a sailor), quickly prepared a rabbit BBQ that delighted everyone.

 L’Île mystérieuse – Jules Verne – End of chapter 4 – My own translation from Italian

What was Verne’s intention when writing this sentence? The book is set during the American Civil War, and the protagonists (the other three are a kid, an engineer and a journalist) are all northeners with progressive anti-slavery views. So is the sentence just a joke?

I find the sentence a bit disturbing, maybe because I know that there is people who would still write it in the same way, people who consciously discriminate ethnic and social minorities, and others who do it just without thinking about it. Yet, while being vegetarian, I am not disturbed by the fact that they are cooking a rabbit. So maybe even the progressive readers of the 19th century were not too bothered by how the other characters treated Nab and Pencroff!

Can anyone else see a future in which animal proteins will be an absurd concept, and therefore also the last bit of the sentence will be considered inappropriate? I think it is quite plausible that this will happen, and I actually hope that it does not take too long!

But for now I’ll go back to reading the book, and enjoying it as it is: an old adventure novel from a visionary writer.