Doug McCrae
Legend
5. As far as "word for word" goes, there are two points here. Firstly, why are you stuck on the stat block? There's a lot more to monster descriptions than a stat block. Now, if we're talking about the full monster description, I'll defer to @Doug McCrae, who has repeatedly posted exactly what the problematic language is. If you don't know it by now, please, I ask you, take the time to read what's actually being written before replying.
This post is a summary, with links to lots of other posts providing supporting evidence and argument.
Identical language – "mongrels" in AD&D 1e and AD&D 2e used to refer to half-orcs, "civilized and savage" "races" in D&D 5e.
This post is about the word "mongrel."
This post covers "civilized and savage" "races."
Extremely similar language and concepts:
Intellectual and moral inferiority
Orcish dominant 'genetic' traits, orcish and goblin high fertility rates and abundant population
Evil as innate and racial
3. Who is complaining about gnolls? Please. I'm really, really curious. When did gnolls become an issue? What in the gnoll description copies, nearly word for word, racist treatises?
4. No, folks don't "map it onto some real world thing". They really don't. No one, AFAIK, is worried about describing gnolls as evil. Nor bugbears AFAIK.
I see all the "savage and brutal" races – bugbears, goblins, gnolls, hobgoblins, kobolds, lizardfolk, orcs – as a problem, due to issues I outline in the summary post.