I think he is referring to the deal between DataTank and AM which was just reached 2 days ago? That is not Selling so much as a barter or trade, if I understand the deal correctly.
What would be AM's benefit from this barter?
I mostly agree with this. There is a huge chance that bitmain/spondoolies/other chips end up in the datatanks.
Although AM does have a closer relationship with DT than you make it sound. Even if they don't primarily use AM chips I expect a few PH will still be used/franchised.
Also 50% better seems a bit of an exaggeration for next gen considering they tested AM HW at 0.6w/gh at the wall.
SP30 chips will be 0.35W/GH at chip level so ~0.4W/GH at wall. You can fit 50% more hashrate for the same power draw. It's not an exaggeration.