[mjn]

Yeah, there have been some discussions of that, but nobody has put together a MediaWiki plugin to do it afaik. Better annotation of regions in general is a longstanding wishlist, so discussions or even citations (or requests for citations) could be attached to a region of text. But then there are problems like how to handle annotations and arbitrary editing/splitting/moving of regions.

As a low-tech solution, you can actually put HTML comments in the source code, which people occasionally do, but it doesn't seem to be a very well-known option. <!-- Do NOT change birth date to XX/XX/XXXX, see talk page --> kind of things sometimes appear in the source. I haven't seen them used for longer discussions, though, just one-line "hey, watch out before you do X" things.

On contentious articles with a long history of debate people will sometimes write a summary on the talk page, so you don't have to read through the whole history of the discussion. On most articles, though, the talk page isn't huge, so I find it easy to glance at before making changes.

[sesqu]

If you have a problem with experts disagreeing about facts, arguing over them, reaching a consensus, and then other "experts" starting up the argument again - it really sounds like you're doing a poor job of communicating the researched consensus in the relevant article.

When that sort of stuff happens, I think you should make sure the incorrect information is referenced in the article as a misconception, or just have the correct information associated with citations. False information should only be erased if it is not "in the wild", so to speak.