It depends on the products.

I sell games, but there are English, French, and Bilingual/Multilingual versions of products. For English version products, my product descriptions and bullet points are in English. For French, in French. For Bilingual/Multilingual, I write both English and French.

I put [Français] in the title for French, [Bilingue/Multilingue] in the title for Bilingual/Multilingual. I also add a phrase to reference the French version of the description below the English (written in French).

For products that are not language specific, such as foods or electronics, you are responsible for providing bilingual labelling and bilingual documents (include in the packaging).

You need to be compliant with Canadian and Quebec legislation.

It is not necessary for English language version products to be bilingual, but it does need to be clear that it is in English. Some customers will see auto-translated text in the product descriptions so may assume that your product is in French, when it really is not. That will result in complaints, negative feedback and reviews, and returns (at your expense).

You need to be thoughtful of these considerations.