Forbes wrote an interesting article about this :
Are Halo And Call of Duty In Danger From Titanfall And Destiny?
I don't think Halo 5 can be Destiny and Titanfall in one game, in the same way Halo can't be Call Of Duty. This is an old IP, in term of video game, and even if I like arena shooters, I have to admit Halo feels pretty old for me.
It has his own style, and without change the gameplay, Halo can't be something else than Halo. Destiny and Titanfall are both new IPs which start with the experience of their predecessors and can go beyond that because Bungie and Respawn had the chance to make a new game, clear the table and create new rules without think about the restriction they had before with their firsts IP.