There's no reason to assume 200 isn't the final number, either. This is a new thing, they had the chance to do it right (having apparently abandoned the armoire), and what they came up with has what is an already low limit and will continue to feel lower as they keep adding more stuff to the game.
What restriction is in place on the backend that would necessitate a 200 limit right now that won't still exist in a year? None of us can answer that question, and until someone can, the idea that the limit is a temporary "new system" thing and not the actual limit is just optimistic speculation. With how restrictive SE is on server resources, I have a hard time finding anything to suggest we'll see that limit change in the medium term.