Well if this is a newsgroups then it has to be compliant with the Internet newsgroups standard and there is a lack of power in this kind of technology.
Every newsgroup need to be on a server. There is no centralized server that takes them all. If they want to create new newsgroups, they don't have the choice, they need to have their own news servers like thousands of other corporations have. Additionally to that, they didn't put any restriction access to this server which mean people can log directly to this server without having to log thru an ISP news server first.
If you use the same news server you used to use, you will still be able to access the newsgroups without having to use msnews.microsoft.com.