Still, in English it's called latex/rubber, right?
Don't they have good translators at Ubisoft?
Why are they using the French word in the English version of the game?
It's such an amateur error in an otherwise amazing game.
For example, in Portuguese we call it "borracha". Now imagine I was writing a text in English and instead of using rubber or latex, I used "borracha".
By the way, when I was a kid, my parents bought me anno 1503. The manual was actually translated to Portuguese. But you know how they translated "hemp" to Portuguese? They called it "cannabis". Like the drug. Well, the hemp plant is indeed from the cannabis family, but you never call "cannabis" to the hemp plant used to make ropes (you can't smoke that one, btw). You just call it "hemp", in Portuguese "cânhamo".
It's the same with using "caoutchouc" in English; you might find a contrived reason to justify it, but in English everyone calls it either rubber or latex (mostly rubber).
Ask any English speaker what are car tires made of; the answer will always be rubber and never "caoutchouc".