The short answer is Yes, it is possible. 

Here is a nice tutorial from Cybrosys, on how to set up an RSS feed in your Odoo app.
After doing this, all you need is to pick which channel you want your feed to be linked with, and temporarily send the feed messages in there, or have a specific channel for your RSS feed.

Alternatively, you can create a single process to read the RSS feed, and when there are new messages, send them to the Discuss channel.