I think the problem here is that the people approving edits need better training on how to use the Markdown diffs. Depending on which Markdown view you're in, it's fairly easy to tell what happened with that link:
In the Markdown diff view, you can easily see that they changed the link in the text to
 and that the
 defined at the bottom clearly points to YouTube.
In the rendered output view, the entire link is crossed out and replaced with a new link which is exactly the same. This only ever occurs when the actual URL behind that text has been changed. You could easily hover over the link to see where it actually points.
It may be sad that we have to look at for phishing attempts here, but I don't believe all the blame can be placed on the users attempting to make these edits. This attempt would be much more obvious using the Markdown diff view. Users already have the tools there to see exactly what's happening.
Some options to make the change more obvious:
List all of the actual hyperlinks (not the text) in a separate box - not very plausible.
Default back to Markdown diff view every time a new suggested edit is loaded - unfavorable.
Show an alert that one of the hyperlinks in the post has changed and should be checked.