What, clicking = good, scrolling = bad? No! We all use both ways to navigate web pages and Wiktionary. It is not about being bad/good thing. It is about removing/keeping choice... And you can use either way at present.
But think, what happens if user look for Russian "язык" or "месяц" etc. with new system? He will be forced to page that got Belorussian definitions. What if person looks for Spanish "justa"? User will get irrelevant Esperanto definition. Italian "cinta"? Ones again, not related page about Indonesian noun. While with interface as it is, I don't even have to click/scroll - information is shown directly on my screen after search of above-words . There dozens(if not hundreds) of thousands articles like that. And as Wiktionary grow, there would be even more.
You say that there is few articles with too huge Contents menu. Legitimate point. But why than we don't fix the real problem - menu itself. For example by adding option to collapse all but top level entrees (e.g. languages). Just the way we got "Hide" option right now. But adding an extra menu to the top of each and every article plus aggressively changing page layout do not sound to me like a right solution for that.
My main point - current system more versatile and more convenient. In a different ways. And contrary to what you say, I do believe, that the chances of article to be edited/corrected related to how many time it was shown/visited/looked into.
Vitally, aka TestPilot