Actually, unnamed sources are essential for news agencies to report the facts on many issues.
Without them, fewer people would come forward, and the public would be left in the dark. Note that even Wikileaks and Snowden did not reveal their sources even though they correctly reported news.  Trump might have convinced you and his other supporters that MSM give false news, but they have been essential to democracy for a very long time. Reputable news agencies always check their sources.
This does not guarantee that Sessions will resign, but it does give a heads-up about what is happening at ground level in the Whitehouse. 
Grow up.