Examiner proof-reading master thesis before submission. Is this allowed? I know someone who is currently writing their master’s thesis. They will be the single author of the document. Our (German) university requires a statement that says something like: ‘I wrote all of this thesis myself unless otherwise specified’, meaning everything not cited is your own work (Eigenständigkeitserklärung).
Now the amount of supervision given for students of course varies between both students and supervisors, but it is generally understood that thesis examiners will read the thesis for grading.
However, one of the advisor’s/examiner’s of my acquaintance offered to proof-read their thesis. This proof-reading can be expected to be both for grammar and content, as the same thing was apparently done by both advisors for the person’s bachelor thesis.
This is not common in my department as far as I can tell. It seems unfair to me: the thesis to be graded was already improved by comments of people who will grade it. In addition, why would they proof-read something for their own examination?
I will most definitely not take any action in this issue. My opinion though is that this is different from proof-reading, e.g., a publication, because the thesis is subject to grading and will not necessarily be published.
Question: Would this situation be considered cheating, micro-managing or just better supervision than average?
(or none of the above?)

This question is somewhat related, but the proof-reading is done by peers instead of examiners. Comments and answers are generally in favour of proof-reading, and one answer mentions proof-reading by supervisors is customary in the UK. I'm not sure whether this applies to Germany, since I haven’t heard about it before.
Whether it is allowed depends on the specific regulations of your university, but your advisor proofreading your thesis and offering suggestions is quite common. I would consider not having a proofreading round to be lazy on the part of the advisor.
Keep in mind that the examiner can still have the initial reading influence the grade. Somebody who submits a perfect thesis that requires no corrections would usually get a higher grade than somebody who submits the same thesis after receiving detailed comments on how to improve it. The proofreading is part of the teaching process, and how well you implement the suggestions is part of the assessment.
What do you think is better from a didactical perspective?

Telling a student that they got a barely-passing grade because X and Y need to be improved

Telling a student that they could improve X and Y by doing Z, and having them do that before assigning a final grade


Clearly, the student will learn much more from option (2).