If this is the case, then why did they spin it off from GWR as a...

If this is the case, then why did they spin it off from GWR as a Gold miner.
Well they are still going to mine it. They just aren't going to build a plant to process it.

When a mill isn't interested in toll treating it is usually because they don't have the capacity to make it worth their while.

Plants that do have the spare capacity will charge a fee per ton of ore processed, or if they are happy with the grades will sometimes buy the ore directly off the miner. The ore purchase agreement has the advantage of giving the miner more upfront profits to cover costs early on and gives the plant owner higher margins per ton processed. In the end it doesn't matter how good or bad the miner is or how good or bad the deposit is - Either way the mill is making money even if they are processing worthless beach sand from a clown.

If a nearby plant is only running at 50 or 75% capacity it does not make business sense not to look to fill that capacity.