I don't really know how to explain this, but I see a weird future in crafting when we convert to CP, not right away mind you. Much of what we have today will remain, but when the CP cap gets raised will they do it slowly or in big chunks? Will there be multiple tiers or one big tier? At least for VR even if they were to raise it to VR20 you still have to level through 17, 18, and 19 before getting to 20 with the associated leveled gear and crafting mats acquired along the way. With CP if you're already over the new raised Cap, you instantly skip over any tiers in between. Let's say the next cap from 160 gets raised to 200 and they created 4 new tiers at 170, 180, 190, and 200; most of the crafting items associated with 170-190 may become a scarce commodity as people above the cap basically skip over it and only those accounts who aren't there yet will be able to farm for them.
This might be a reason for the Potency rune change and why they decided to have Potency runes for sale at vendors, they may have foresaw this outcome when they plan on raising the cap. If you were skip over the minimum CP in order to acquire 170, 180, and 190 Potency runes; you may never see them in your game time when places where they be obtainable is automatically scaled to 200. Only those who are below the cap will ever be able to acquire them in the field, dungeons, or as rewards; those over the Cap players will only see Max Cap items every time they raise the CP cap. You're just going to have a lot of low quantity middle ground caps when the disparity of different CP caps come into play.