This notion of disabling the Next button when at the end of a module has been discussed before. It can be done. Someone might have even written code to do it. I seem to remember discussing writing code to do it and what would be required. While possible, it's something that would need to be done at the [sub]account level since it would involve custom JavaScript. Faculty could not implement it on their own (that's a good thing for consistency across courses and helps the students).
You might think about using custom CSS instead of JavaScript, but CSS selectors don't allow you to select based on text. The only difference between the next module item within the current module and the next module is in the text of the tooltip. The tooltip adds a strong (bold) "Next Module:" when it's at the end of a module.
JavaScript could pick up on that text, but that is very language (English in my case) specific and not something good to query against unless everyone uses the same language -- or at least you only care about hiding the button for those who use the primary language.
Since that implementation would be for everyone in that subaccount, the change would need to be agreed upon by everyone using it. It's definitely not a "Joe can do this" while "Jane does that" kind of thing.
On the other hand, @TrishaMeyer1 makes a good suggestion about using a stop page that can be added to the end of each module. That allows faculty the control over what they want.
I cannot even say it should be a "congratulations! you've finished the module" page, because that's not true if the items aren't enforced in a sequential manner. Going back to the modules page may not be the best decision, either. That's basically the Home link for people, so it duplicates functionality. On the other hand, letting them know that Next takes them to the next module could be informative.
The whole situation isn't clear-cut. I use the module system for badges, so I don't want the students using the previous or next button at all, otherwise, they miss the important stuff that isn't required for a badge. For other people, it can make sense. Canvas tries to make it work well for the middle group of users. Those with demands on the high or low end have to work around things to get what they want.
I'm not sure how big of a problem this really is. It may depend on the students. Most of mine are able to figure out when the topics change. In reality, few of mine probably use the Next button anyway, they just jump to assignments that appear on the To Do list or the Grades page (that have 0's because they missed it).