There are some disadvantages making different apps for different languages:
- you outlined the first one, which is update your app.
- that can be confusing on the store. If I look for your application and I get 5 different versions that is worse than having a single version that automatically adopt my language.
- you will get less download. Your app is visible depending on the note and the download count. With, for example, 5 app, you will potentially get 5 times less download than a single app. This is a, in my opinion, the most important reason.
- think about, if you make a "pro" version, you will have like 2*(number of language) apps. that will be a potential big mess.
- If a user change its smartphone settings (move from english to french for example) the app will automatically change language. With your solution he will have to re download the right one.