Whilst I would accept Nemmersdorf stating the writing is authentic, the original poster should outline more. I realise they will attempt everything to convince people to support an agreement but very few are for an agreement. Everyone I know is anti-agreement. One or two here and there in Ireland in SSPX circles are pro- agreement but they come from an Indult background so a pro-agreement position is to be expected from them.
From what I have found, it appears to be authentic, although it is unknown why the Bishop would use this particular language.
To say that none of the conversation was true is too broad an interpretation.
The Bishops are in a delicate situation with Menzingen, and one can see why such a disclosure could create further problems for them.
The priests and the Bishop are all honorable men but at times inaccurate characterizations of events can set in motion unforeseen consequences such as this.