So it appears i was correct, and a lot of Space Marine chapters in the current dark imperium setting are still making standard marines alongside primaris to still be able to use the standard Space Marine gear.
From the recent warhammer community 500 stores article:
"84. Most Chapters now have the means and technology to create Primaris Space Marines of their own (drawn from their usual recruitment worlds), though many still choose to create standard Space Marines as well for their more flexible and readily available equipment and combat doctrines."
There you have it.
Also another interesting fact on Primaris marines from the same article:
"85. Much like the first Space Marines of the Great Crusade, the first wave of Primaris Space Marines were almost universally Terran- or Martian-born"
I suspected this was the case after reading War of Secrets in which the Dark Angel primaris are clearly terran or martian, and the new Space Wolves codex which states that the primaris Space Wolves sent by Gulliman were not fenrisian (and implies they were Terran). I guess that means the Primaris like Bjarni and Felix from the Dark Imperium books were an initial batch taken from their respective legion homeworlds, and then when Cawl started making them in numbers he turned to the large populations of terra and mars for recruits. Possibly also because he and/or gulliman didn't want other chapters and primarchs to know what was going on.