Wagtail (https://wagtail.io/) is a nice CMS layer on top of django and python. Wagtail is special in that it doesn’t have a build-in user-facing front end. You are invited to build your own that perfectly suits your needs. Wagtail is opinionated in that sense. It does have a nice admin interface for adding content.
Through google summer of code, an earlier idea he had on live blogging was added to wagtail. It is intended for live blogging a sports match, for instance. Lots of small messages.
It can grab input from slack or telegram. Of course, you can also use the admin interface or a REST api.
There is a bit of a workflow mechanism. You perhaps want to format the first line of an incoming message as a title.
There are multiple ways to set up the blog-viewing webpage. Interval polling, long polling, websockets. Websockets are the best option, but it takes more setup effort. Interval polling is the easiest option: just plain http.
My name is Reinout van Rees and I work a lot with Python (programming language) and Django (website framework). I live in The Netherlands and I'm happily married to Annie van Rees-Kooiman.
Most of my website content is in my weblog. You can keep up to date by subscribing to the automatic feeds (for instance with Google reader):