We'd like to have regular newsletters go out to subscribers, the content would be a few dedicated topics (mainly things from the news, but in more detail, and perhaps a collection of other news items and research etc. It doesn't have to be regular on a schedule, but rather just refines and is sent out when it reaches a satisfactory state of completeness.
Once a platform has enough members and enough activity, it becomes worthwhile to have a role dedicated to managing the platform's content. The basic blog-style site news format can then be extended to a proper newsletter format which can be viewed online like normal, emailed or printed as a booklet. The newsletter acts as a portal for members to keep abreast of current affairs and concerns within the platform and also keeps all platforms up to date with the project and the world as a whole.
Newsletters are articles which are collaborated on in the same way as a channel because they need to be in a complete state ready for publication and distribution on their regular cycle.