Would it be smart for a consumer goods brand in the Gulf market to use multi language on products' packaging?

Yes it is very helpful on customers. This is an additional point to sell your product easily because they don't need to approach someone for a simple information besides it is not only one language that each country speaks and there are lot of expats.

The most obvious and practical answer, is yes.However, what is truly elusive is the design of the product packaging. Attempting to cram volumes of information that the translates the other makes things unattractive.