Thank you for explaining so clearly and eloquentlyI think you miss a big point, there isn't really a word that you can translate in any language to be literally racist, even the ones which were once used in the US like "negro" (in fact stolen from Latin America) but we won't get into that.
What made it a racist term as like "coloured" in the US and UK and now "urban" in some context now in the UK was the context around it and the culture, not the words specifically.
The context being it is now culturally unacceptable in Western Culture to refer to someone by their race, no matter what word you use.
The word black in English is not a racist term, but if I refer to someone who is black as "Hey black" there will be a problem in the UK, this isn't a language issue as really its more a cultural one which shows the cultural differences between Western culture and Latin American.
Describing features and race is prevalent in their language and widely accepted in their culture.
Focusing on the actual word used misses this nuance, equally, there could be an issue if he used the term "chinito"
With all that said, I don't believe we can expect Cavani to know all of this as someone who has hardly lived in the UK or US, but I'm sure he will probably not post something like that on social media again. Also its not for one culture to preach to another what is right or wrong.
He just happens to be playing in a UK based league which has UK based rules and guidelines.