On the one hand, it makes sense, and on the other, you have to think about Construct as a tool for very beginners (children ?) who do not speak English, don't understand it and will probably understand French better.
That is how Construct is designed in English and most system expressions have an actual meaning in English.
Translating them was a way to bring this meaning to French as well.
Finally, even though translated, when auto-completed the expression will provide the original expression in English within Construct and also the input field, as you are entering the expression will contain the English version only, allowing people to still be exposed to the dev/English term for the long run.