My example is this drastic edit to the question I had replied to, which is a drastic rewrite.
Are the original questioners asked to approve of the change even though their reputation is below 10?
Regarding that particular question, it's not been drastically edited. Formatting and grammar has been improved, that's pretty much it. (look closely).
But in general, radical edits get rejected as "too radical". Note that the OP gets a notification of an edit or a suggested edit, so s/he can always rollback or reject it.