What do you think will happen to Jul 'Mdama in Spartan Ops? Since Spartan Ops will lead into Halo 5, so I wonder what will happen to him.
I think he’ll live.
Oh, and we get to meet the librarian!
I thought of this too, however I think M’Dama’s fate lies with that of Majestic and Crimson leading a joint attack on him. Would make for an epic boss fight. H2 Tartarus fight anyone? 
Don’t be too sure on that, the librarian I mean.
Jul M’dama has to live in order for the Storm Covenant to have any relevance in Halo 5. And probably expect to see the Flood return half-way through 5.