We don’t know how big the forge canvas will be yet.
Given what we saw in Halo 5, it won’t be that big as compareable to actual BR maps.
The fans already hate the game and how it handles cosmetics and challenges enough.
This would add more fuel to the fire.
Tell that to Fortnite and CoD Warzone.
That is my concern there. I feel like they will be used as transportation only, no shooting or running people over with them. Even so, I think they will give you just a Mongoose, maybe a Razorback too. Because I cannot imagine flying a Banshee or driving a Scorpion without being able to fire their guns.