if you read further down
As for non-Apple NVMe drives, (Samsung), to this date the tests I have done are:
Mac Pro late 2013 : doesn't work
MacBook Air early 2014 : doesn't work
MacBook Air early 2015 : works
MacBook Pro 15" early 2015 : doesn't work
So there seems to be some inconsistencies in that post. I agree with @hey_yo_ that support was only added from skylake but with apple who know.
On closer inspection, the connector the ssd uses is not msata hence the need for the adapters so without going for the official ssds, these (https://www.transcend-info.com/Products/Solution_detail.aspx?no=8) or the OWC Aura
EDIT: On further research, there are mentions of apple using a proprietary storage controller(but I cannot confirm) this would mean normal ssds will not work. I would suggest getting one of the compatible sdds listed above there are others if you search