I found the ticket T7582 in question, “Disallow ia_archiver on user and user_talk pages (robots.txt)”; it was apparently declined and superseded by ticket T16720, “robots.txt”. The history of this is a bit complicated for me to parse; I haven’t worked on the programming side of Wikipedia/Wikimedia at all, only as an editor.
My understanding is that edits only get struck from the publicly visible page history under a very limited set of circumstances — for example, copyright violations, serious violations of the Biographies of Living Persons policies, or serious harassment of other editors. I have particular experience with the latter as I was stalked by a sociopath on Wikipedia for six months, and there is really no good reason to keep a publicly visible record of my ordeal either in Wikipedia or in the Internet Archive.
However, I can understand the concern when it comes to political articles, as Wikipedia’s admins and oversighters (a small group that has access to the most sensitive stricken data) are humans who are flawed like all of us, so they aren’t immune from corrupting influences. There is no perfect solution here.