You need to read the clause again.
Its not that they have to take a shipment every 60 days, it's that a schedule is drawn up, and they have a 60 day buffer after each agreed shipment to take it or let it pass.
That schedule hasn't been published, so we don't know what has been agreed. We do know that A40 were pushing for monthly with comments from MC. I forget if that was @luanboo or @el Jefe who provided that wonderful Intel, but it was definitely there.
There may be multiple layers to this. If Burwill's ramp up is taking longer than expected (completely unsubstantiated, but assumed based on the annual capacity they should be able to take if at full operation), while Bald Hill's upgrades will produce more than originally expected, it makes sense to bring in a third party.
The first part of the negotiations may have been to address the current situation, then moving on to upgraded plant production, and bringing a third party in to iron out the details. Who gets which shipments, what dates, how is pricing set etc etc.
If there's a new party, I would give a slim chance to there also being discussion of DMS2. I would be very surprised if there is a prepayment or anything like that for DMS2 just yet, without more exploration having been done, but they could very well have something like that factored into the new agreement, to be dealt with later in the year.
That's my two cents' worth, let's see what gossip emanates out over the next week.
Cheers