I didn’t see the dev stream, but going off how you described it this seems like a totally valid point that DE should’ve caught earlier. Don’t use the word savage anywhere near something that’s based on Africa or African culture, period, now and forever.
The response you got was about what I expected. Warframe reaches such a wide range of people that the community has both the nicest, most generous members and also just the grimiest internet creeps. Even in a case this clear cut, that can also be chalked up to an accidental oversight, there’s going to be someone that tries the “You’re being too sensitive” defense to avoid engaging with the actual issues. It’s still worth talking about in the hopes that someone higher up sees it and realizes that hey, this is pretty gross and easy to fix.