Imagine for the fun of it at the end of the game instead of using planets you pilot death stars and blow each other up. Not very original but it's real planetary annihilation.
That's what is implied that the metal world will be. Besides, what's wrong with the end game being massive swarms of units?
The human mind wants to take a weapon and just make it bigger and more destructive preferably with a huge boom. We can't help wanting giant planet destroying death Stars .
If the metal planet can transmogrify into a giant pacman style planet eating...er thing. Then life will be perfect (for a little while)
we may get deathst...errrrr metalplanets with reactivateable weapons that could be used for planetbusting ...
Indeed this has been confirmed, however details as to the implementation and design of said weapon is yet to be announced. Be patient... when Uber promises destruction they deliver.
If I may make a suggestion - go and play a game called Zero-K and then come back and tell me that the Detriment doesn't completely ruin the late game. We play a fair bit of Zero-K internally and everyone agrees that it's a really really stupid unit.