To avoid including information such as number of revisions and total editing time, I can simply proceed to File > Properties, open the General tab, and clear the Apply user data check box.
Of course, instead of clearing this check box for each new document, it is much better to disable it for the template (I use a custom one).
However, as I discovered, if you disable it for the template, it also makes impossible for Writer to detect if the template has been changed when you open documents based on it.
I have reported it as a bug: https://bugs.documentfoundation.org/show_bug.cgi?id=145047, but nobody answered or confirmed it yet.
Is there a workaround?