While I appreciate the effort, gdpr has some very stupid parts which clearly show that it wasn't properly discussed with experts.
For example: Information that somebody had received can never be reliably deleted, any attempt to do so will only make people use alternative clients. The only part of the service that I control is the server, especially in open source, and if people accept that others will see their data, it cannot be "unseen". I can delete it from my side so no one else will receive it _from me,_ but please don't make laws that enforce me to write client features no one wants because anyone familiar with the market knows that this will simply produce an alternative.