Collaboration is no longer possible on unpublished posts

Usecase:
A blog post needs to be redacted by multiple users before it gets published.
User A creates the blog post and then sends a link (by chat or email) to user B. User B wants to read the blog post and potentially make some changes on it. Same can happen for a number of other users. When they all agree, they publish the blog post.

Currently, this is no longer possible, as view rights are explicitly set to user A when they create the blog post, thus all the other users lose this right. This only works if user A gives explicit rights also to users B, C, D, etc. or users B, C, D are admins.

However, even if they are admins and they can view / edit the page, when editing the page they will receive view rights explicitly when editing the page which are not removed by the publication process of the blog (issue reported as BLOG-172) because the blog app does not support this usecase of collaboration on unpublished posts.