(Question) what do we know Alien troopers and The so called "Covenant Masters"?

https://youtu.be/53C87R4MHxA?si=mZumERt2lef2X-XU (To see it go near the end of The Video)

I heard of Fleet masters, Shipmasters etc but Never Covenant Master is that what Arbiter is? Or it's a different thing? And as for The Alien Trooper I seen 3D Models in The Google which looks interesting however do you guys we see them in the Future or only going to be Silent Canon Like The Shadow or The Secret Soldier Prophets?