I think there's some confusion regarding what the tests that reveal the higher recoveries reveal.
I would say yes they are going to recover more metal. Though CZI has grabbed a couple of a fee kicks with using a higher grade sample and choosing to avoid the hard to recover violarite. (Which we’d call foo- foo dust after the legend of the foo- foo bird). http://www-personal.umich.edu/~bbowman/birds/humor/foo_bird.html
If one want's to know the expected head grade for the project one should use all the drilling data in the PFS not that of the bulk samples cobbled together for test-work. It probably hasn't dropped unless they are struggling for tonnes which I expect we’re not, especially “marginal” tonnes.
What we’re seeing here is the true value of a PFS (or successive studies). They are done specifically to fine tune the mining and processing route.