> I don't necessarily personally feel like preserving European Portuguese in amber is a worthwhile goal (anymore than it is productive for Brits to be prickly about the meteoric rise of US English).
That's easy to say when you're not on the other end of US defaultism.
To be fair, it is only natural: Portuguese itself only came to be because the Roman Empire conquered the Lusitan land [1], a lot of English comes from Norman French from the Norman conquest [2], the Americas didn't speak European languages until 500 years ago or so, etc.
If you give enough time, all languages will change, and some of them because of major political changes/conquests
I'm not saying that is good nor that is bad, looking through the anthropology lens there's no value judgement.
Besides, differently from your shocking examples, cultures and languages don't "die" as you seem to imply, they evolve, and that part is natural and not bad or good. Portuguese (and English) will change we liking it or not
That's easy to say when you're not on the other end of US defaultism.