So far I have been researching and it looks like their not going to be there… If so that would be kinda weird don’t you think? Cause shouldn’t they show off a Teaser Trailer for Halo 5 and show off some stuff for Spartan Assault.
If you have been researching and you didn’t see their name on the list then clearly they won’t be there.
Spartan assault should be payable there.
But this is the wrong forum section.
Yes, it’s confirmed they’ll be there.
We have a couple threads like this in General Discussion. 
https://forums.halowaypoint.com/yaf_postst213690_If-343-announced-a-new-Halo-title-at-E3.aspx